7th Class Science Physical and Chemical Changes Question Bank

done Physical and Chemical Changes Total Questions - 112

• question_answer1)
  The reason for a physical change to be named as such is that the:
  A)
  change occurs only in physical properties done clear
  B)
  transfer of energy takes place done clear
  C)
  is a reversible change done clear
  D)
  All of the above done clear
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• question_answer2)
  When ice is heated, it changes to water and water on further heating gets converted to steam. What happens when steam is condensed?
  A)
  A new substance is formed done clear
  B)
  No new substance is formed done clear
  C)
  Gaseous phase changes to liquid phase done clear
  D)
  Both (b) and (c) are correct done clear
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• question_answer3)
  A change is a chemical change when it is accompanied by:
  A)
  energy change done clear
  B)
  formation of new substances done clear
  C)
  change in chemical properties done clear
  D)
  All of the above done clear
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• question_answer4)
  Which of the following will be observed if an apple slice is left exposed to air?
  A)
  It under goes oxidation and become brown in colour done clear
  B)
  Appearance of brown colour on the surface of apple slice is caused by a chemical reaction between air and enzymes done clear
  C)
  Both the above are correct done clear
  D)
  None of these done clear
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• question_answer5)
  The shipping industry has to bear huge financial loss because of rusting of ships. The rusting of ships occur because:
  A)
  the body of ship is always in contact with water. done clear
  B)
  the air around the ship is humid. done clear
  C)
  presence of salts in sea water speed up the process of rusting. done clear
  D)
  All of the above done clear
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• question_answer6)
  Which is the best method to prevent rusting?
  A)
  Painting                       done clear
  B)
  Greasing done clear
  C)
  Galvanization     done clear
  D)
  Precipitation done clear
  View Solution play_arrow

• question_answer7)
  A change in which the original substance can be obtained back by change of conditions is called:
  A)
  reversible change         done clear
  B)
  physical change done clear
  C)
  chemical change          done clear
  D)
  Both (a) and (b) done clear
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• question_answer8)
  When magnesium is burnt, heat and light are produced. The burning of magnesium is a:
  A)
  reversible change done clear
  B)
  physical change done clear
  C)
  chemical and exothermic change done clear
  D)
  chemical and endothermic change done clear
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• question_answer9)
  Change of milk to curd is a:
  A)
  physical change done clear
  B)
  chemical change done clear
  C)
  Both physical and chemical change done clear
  D)
  Neither physical nor chemical change done clear
  View Solution play_arrow

• question_answer10)
  Expansion on heating and contraction on cooling of metals is a:
  A)
  chemical change          done clear
  B)
  physical change done clear
  C)
  irreversible change       done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer11)
  Which of the following changes is accompanied by sound?
  A)
  Photosynthesis done clear
  B)
  Spoilage of food done clear
  C)
  Explosion of fire works done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer12)
  Hydrochloric acid is added to a beaker containing a piece of zinc. Zinc chloride is formed and hydrogen gas is released. This is an example of:
  A)
  a chemical reaction     done clear
  B)
  a physical change done clear
  C)
  Crystallization  done clear
  D)
  None of these done clear
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• question_answer13)
  Which of the following statements is correct?
  A)
  Evaporation is a chemical change done clear
  B)
  Digestion of food is a chemical change done clear
  C)
  Burning of paper is a physical change done clear
  D)
  All of the above done clear
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• question_answer14)
  Which of the following statements is correct?
  A)
  When coal is burnt no new substance is produced done clear
  B)
  Rust is not formed in the absence of air or oxygen done clear
  C)
  The fizz that comes out when a soda bottle is opened is due to a chemical change. done clear
  D)
  Respiration is a physical process done clear
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• question_answer15)
  Which of the following statements is correct?
  A)
  Cutting of wood into pieces is a chemical change. done clear
  B)
  Conversion of manure from leaves is a physical change. done clear
  C)
  Iron pipes coated with zinc do not rust easily. done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer16)
  Which of the following statements is correct?
  A)
  Iron and rust are same substance. done clear
  B)
  Rusting of iron is a chemical change. done clear
  C)
  Removal of rust from surface of iron is chemical change. done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer17)
  The process used to prevent rusting of iron, in which a thin coat of zinc is provided over iron surface. This process is:
  A)
  galvanization               done clear
  B)
  electroplating done clear
  C)
  painting in zinc            done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer18)
  Chemical change that is accompanied by evolution of heat energy is:
  A)
  physical chemical change done clear
  B)
  exothermic chemical change done clear
  C)
  endothermic chemical change done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer19)
  Characteristic of matter exhibited without a change in its identity is:
  A)
  physical property         done clear
  B)
  chemical property done clear
  C)
  thermal property          done clear
  D)
  None of these done clear
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• question_answer20)
  In which one of the following situations chemical reaction does not occur?
  A)
  Common salt is exposed to air done clear
  B)
  Coal is burnt in air done clear
  C)
  Sodium is placed in water done clear
  D)
  Iron is kept in moist air done clear
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• question_answer21)
  Glowing of an electric bulb is a ________ change.
  A)
  physical done clear
  B)
  chemical done clear
  C)
  Both physical and chemical done clear
  D)
  None of these done clear
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• question_answer22)
  Why rusting of iron is a chemical change?
  A)
  Because it changes its colour done clear
  B)
  Because it makes iron powdery done clear
  C)
  Because a new substance is formed done clear
  D)
  None of these done clear
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• question_answer23)
  Adding salt to water makes it salty. Which of the following statement is true regarding this change?
  A)
  It is a chemical change because a new substance is formed done clear
  B)
  It is a physical change because the original substances can be recovered done clear
  C)
  It is a chemical change because there is exchange of heat done clear
  D)
  It is a physical change because there is a slight change in colour. done clear
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• question_answer24)
  Pooja took a candle in a vessel and heated the vessel. Even though the candle did not bum, it changed its shape and state. What kind of change is this?
  A)
  Irreversible change       done clear
  B)
  Physical change done clear
  C)
  Chemical change         done clear
  D)
  None of these done clear
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• question_answer25)
  An oxide of iron from the following is
  A)
  mud                             done clear
  B)
  dust done clear
  C)
  rust                              done clear
  D)
  None of these done clear
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• question_answer26)
  Which of the processes below involves change in state?
  A)
  Evaporation                 done clear
  B)
  Condensation done clear
  C)
  Sublimation                 done clear
  D)
  All of the above done clear
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• question_answer27)
  Which of the following is necessary for rusting of iron?
  A)
  Water              done clear
  B)
  Air done clear
  C)
  Heat energy                 done clear
  D)
  Both (a) and (b) done clear
  View Solution play_arrow

• question_answer28)
  Which of the following is a physical change?
  A)
  Burning of kerosene done clear
  B)
  Lighting an electric bulb done clear
  C)
  Heating sugar in a pan done clear
  D)
  Heating sulphur with iron fillings to red-hot state. done clear
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• question_answer29)
  Complete the following analogy Electrolyzing: chemical change :: crystallization
  A)
  Thermal change           done clear
  B)
  Physical change done clear
  C)
  Neutralization              done clear
  D)
  Fast change done clear
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• question_answer30)
  Which of the following is not a mixture?
  A)
  Air                               done clear
  B)
  Pure water done clear
  C)
  Sea water                    done clear
  D)
  Lemonade done clear
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• question_answer31)
  Change in size, shape and state of a substance is a:
  A)
  Chemical change         done clear
  B)
  Cyclic change done clear
  C)
  Physical change    done clear
  D)
  None of these done clear
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• question_answer32)
  Which one of the following substance is a mixture?
  A)
  Copper            done clear
  B)
  Salt done clear
  C)
  Sugar                           done clear
  D)
  Muddy water done clear
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• question_answer33)
  Which of the following is not a chemical change?
  A)
  Digestion of food done clear
  B)
  Conversion of liquified petroleum gas into gas on opening the cylinder. done clear
  C)
  Photosynthesis done clear
  D)
  Production of biogas from animal waste done clear
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• question_answer34)
  Complete the following equation of rusting of iron. \[\text{Iron(Fe)+A+moisture}\to \text{B}\]
  A)
  A = Oxygen, B = Carbon dioxide done clear
  B)
  A = Water, B = Oxygen done clear
  C)
  A = Oxygen, B = Rust (iron oxide) done clear
  D)
  A = Carbon dioxide, B = Oxygen done clear
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• question_answer35)
  What is the formula of rust?
  A)
   \[\text{F}{{\text{e}}_{\text{3}}}{{\text{O}}_{\text{4}}}\]                       done clear
  B)
   \[\text{F}{{\text{e}}_{\text{2}}}{{\text{O}}_{\text{3}}}\] done clear
  C)
   \[\text{FeO}\]                                     done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer36)
  DIRECTIONS: Match Column-I with Column-II and select the correct answer using the codes given below the columns.  

  Column - I	Column - II
  (A) heat energy is evolved during the reaction	(p) Physical change
  (B) Heat energy is absorbed	(q) Chemical change
  (C) Digestion of food in the body	(r) Exothermic reaction
  (D) Melting of wax	(s) Endothermic reaction

  A)
  (A) \[\to \] (p), (B) \[\to \] (q), (C) \[\to \] (r), (D) \[\to \] (s) done clear
  B)
  (A) \[\to \] (q), (B) \[\to \] (p), (C) \[\to \] (r), (D) \[\to \] (s) done clear
  C)
  (A) \[\to \] (r), (B) \[\to \] (s), (C) \[\to \] (p), (D) \[\to \] (q) done clear
  D)
  (A) \[\to \] (r), (B) \[\to \] (s), (C) \[\to \] (q), (D) \[\to \] (p) done clear
  View Solution play_arrow

• question_answer37)
   DIRECTIONS: Match Column-I with Column-II and select the correct answer using the codes given below the columns.

  Column - I	Column - II
  (A) Pasteurization of milk	(p) Physical change
  (B) Explosion of fireworks	(q) Rusting of iron
  (C) A chemical equation	(r) Physical change
  (D) Formation of iron oxide	(s) \[Magnesium\text{ }\left( Mg \right)+Oxygen~({{O}_{2}})\to Magnesium\,oxide\,(MgO)\]

  A)
  (A) \[\to \] (s), (B) \[\to \] (p), (C) \[\to \] (q), (D) \[\to \] (r) done clear
  B)
  (A) \[\to \] (r), (B) \[\to \] (p), (C) \[\to \] (s), (D) \[\to \] (q) done clear
  C)
  (A) \[\to \] (r), (B) \[\to \] (p), (C) \[\to \] (q), (D) \[\to \] (s) done clear
  D)
  (A) \[\to \] (p), (B) \[\to \] (r), (C) \[\to \] (s), (D) \[\to \] (q) done clear
  View Solution play_arrow

• question_answer38)
  DIRECTIONS: Read the passage given below and answer the questions that/allow. Passage - 1 Take a small quantity of copper sulphate crystals and dissolve it in a small quantity of water to obtain blue coloured solution. Add a few drops of dilute sulphuric acid. Now, put 3-5 medium sized iron nails in it. Soon the colour of blue solution changes to green and a brown deposit appears on the iron nails. Change of colour from blue to green in the above activity represents:
  A)
  physical change           done clear
  B)
  chemical change done clear
  C)
  Both of the above        done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer39)
  DIRECTIONS: Read the passage given below and answer the questions that/allow. Passage - 1 Take a small quantity of copper sulphate crystals and dissolve it in a small quantity of water to obtain blue coloured solution. Add a few drops of dilute sulphuric acid. Now, put 3-5 medium sized iron nails in it. Soon the colour of blue solution changes to green and a brown deposit appears on the iron nails. Green colour of the solution is due to the formation of....................
  A)
  Copper sulphate          done clear
  B)
  Iron sulphate done clear
  C)
  Copper metal               done clear
  D)
  none of these done clear
  View Solution play_arrow

• question_answer40)
  DIRECTIONS: Read the passage given below and answer the questions that/allow. Passage - 1 Take a small quantity of copper sulphate crystals and dissolve it in a small quantity of water to obtain blue coloured solution. Add a few drops of dilute sulphuric acid. Now, put 3-5 medium sized iron nails in it. Soon the colour of blue solution changes to green and a brown deposit appears on the iron nails. Brown deposits that appears on iron nails Is due to deposition of:
  A)
  iron on iron nails         done clear
  B)
  copper on iron nails done clear
  C)
  copper sulphate on iron nails done clear
  D)
  iron sulphate on iron nails done clear
  View Solution play_arrow

• question_answer41)
  DIRECTIONS: Read the passage given below and answer the questions that/allow. Passage - 2 Salt dissolved in water forms solution. Salt holding capacity of water is limited. When this limit is reached the solution is said to be saturated. Excess salt, if any, separates out from a saturated solution in the form of salt crystals. These crystals are more than 90% pure. We make use of the process of crystallization for obtaining salt from sea water. The crystals that are obtained after crystallization are:
  A)
  10%pure done clear
  B)
  between 20% to 50% pure done clear
  C)
  between 50% to 90% pure done clear
  D)
  more than 90% pure done clear
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• question_answer42)
  DIRECTIONS: Read the passage given below and answer the questions that/allow. Passage - 2 Salt dissolved in water forms solution. Salt holding capacity of water is limited. When this limit is reached the solution is said to be saturated. Excess salt, if any, separates out from a saturated solution in the form of salt crystals. These crystals are more than 90% pure. We make use of the process of crystallization for obtaining salt from sea water The process of crystallization is used to obtain pure compound from an impure sample. Which of the following statements is correct?
  A)
  Process of crystallization is an example of a chemical change. done clear
  B)
  Process of crystallization is an example of a physical change. done clear
  C)
  Process of crystallization involves an irreversible change. done clear
  D)
  All the above are correct. done clear
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• question_answer43)
  DIRECTIONS: Read the passage given below and answer the questions that/allow. Passage - 2 Salt dissolved in water forms solution. Salt holding capacity of water is limited. When this limit is reached the solution is said to be saturated. Excess salt, if any, separates out from a saturated solution in the form of salt crystals. These crystals are more than 90% pure. We make use of the process of crystallization for obtaining salt from sea water A solution in which no more solute can be dissolved is called
  A)
  unsaturated solution    done clear
  B)
  saturated solution done clear
  C)
  true solution                 done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer44)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Tearing of a paper sheet into small pieces is a chemical change. Reason (R): It is not possible to rejoin small pieces of paper to get back the original paper sheet.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer45)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Formation of rust is a chemical change. Reason (R): For formation of rust, iron must be exposed to air and water.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer46)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Burning of a candle is a physical change. Reason (R): The products formed by burning a candle cannot be easily converted back to original candle.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer47)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Some changes which result in formation of new substances are called chemical changes. Reason (R): Chemical changes are irreversible.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer48)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Burning of paper is a physical change. Reason (R): The products formed on burning of paper cannot be converted back to paper.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer49)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Coating an iron sheet with a layer of zinc is called galvanization. Reason (R): The process which converts iron to iron oxide in the presence of moisture and air is called rusting.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer50)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Decay and decomposition of dead organic matter (leaves and dead animal bodies) by microbes is a chemical reaction. Reason (R): In a chemical change original substance and its properties are changed to new material with new properties.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer51)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Explosion of a fire cracker is a physical change. Reason (R): A physical change is a reversible change.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
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• question_answer52)
  DIRECTIONS: Read the following two statements carefully and choose the correct options. (i) Lime water turns milky due to presence of calcium bicarbonate. This is a confirmatory test of\[\text{C}{{\text{O}}_{\text{2}}}\]. (ii) Digestion of food and melting of wax are considered as similar type of changes.
  A)
  Statement (i) is correct while statement (ii) is incorrect. done clear
  B)
  Statement (ii) is correct while statement (i) is incorrect. done clear
  C)
  Both statements are correct done clear
  D)
  Both statements are incorrect. done clear
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• question_answer53)
  DIRECTIONS: Read the following two statements carefully and choose the correct options. (i) Condensation of steam is not a chemical change (ii) Physical change is a permanent and irreversible change
  A)
  Statement (i) is correct while statement (ii) is incorrect. done clear
  B)
  Statement (ii) is correct while statement (i) is incorrect. done clear
  C)
  Both statements are correct done clear
  D)
  Both statements are incorrect. done clear
  View Solution play_arrow

• question_answer54)
  DIRECTIONS: Read the following two statements carefully and choose the correct options. (i) Cutting of wood is considered as a chemical change (ii) Crystallization is a physical change
  A)
  Statement (i) is correct while statement (ii) is incorrect. done clear
  B)
  Statement (ii) is correct while statement (i) is incorrect. done clear
  C)
  Both statements are correct done clear
  D)
  Both statements are incorrect. done clear
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• question_answer55)
  DIRECTIONS: On the basis of following diagram/ picture answer the questions given below: Which of the following changes represent a chemical change?
  A)
  Only (i)                        done clear
  B)
  Only (ii) done clear
  C)
   (i) and (ii)           done clear
  D)
  None of the two done clear
  View Solution play_arrow

• question_answer56)
  DIRECTIONS: On the basis of following diagram/ picture answer the questions given below: What is the name of the process that is shown in the given figure?
  A)
  Evaporation                 done clear
  B)
  Sublimation done clear
  C)
  Neutralization              done clear
  D)
  Crystallization done clear
  View Solution play_arrow

• question_answer57)
  Direction:  Look at the following diagram carefully and answer the following questions: Rusting of iron nail will be faster in which of following test tube.
  A)
  A                                  done clear
  B)
  Both A and B done clear
  C)
  B                                  done clear
  D)
  Equal in A, B and C done clear
  View Solution play_arrow

• question_answer58)
  Direction:  Look at the following diagram carefully and answer the following questions: On the basis of given figure read the following statements and choose the correct option. (i) Oil present in test tube A cut off the presence of air. (ii) \[\text{CaC}{{\text{l}}_{\text{2}}}\] is used for absorbing moisture in the test tube C. (iii) Rusting decreases on adding saline water in test tube B.
  A)
   I and III are correct done clear
  B)
   I and II are correct done clear
  C)
  Only III is correct done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer59)
  DIRECTIONS: On the basis of following diagram/ picture answer the questions given below: Which of the following represents a physical change?
  A)
   (i) and (ii)                   done clear
  B)
   (ii) and (iii) done clear
  C)
   (i) and (iii)       done clear
  D)
  only (i) done clear
  View Solution play_arrow

• question_answer60)
  Liquefied Petroleum Gas (L.P.G) used as kitchen fuel is supplied in the liquid form in the gas cylinders. When it comes out from cylinder it comes out as a gas which bums. Which of the following statements is correct?
  A)
  The process of conversion of liquid to gas involves a chemical change. done clear
  B)
  The process of burning gas is a chemical change. done clear
  C)
  Both the above are correct. done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer61)
  Choose correct option on the basis of statement (i) and (ii) (i) When hydrogen bums in oxygen, water is formed (ii) When water is electrolyzed, hydrogen and oxygen are formed.
  A)
   (i) is a physical change and (ii) is a chemical change done clear
  B)
   (i) is a chemical change and (ii) is a physical change done clear
  C)
  Both (i) and (ii) are physical changes done clear
  D)
  Both (i) and (ii) are chemical changes done clear
  View Solution play_arrow

• question_answer62)
  Select the one that is not a chemical change:
  A)
  Dissolution of ammonia in water done clear
  B)
  Dissolution of carbon dioxide in water done clear
  C)
  Dissolution of oxygen in water done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer63)
  ...................... is a chemical change
  A)
  Mixing of paint colours done clear
  B)
  Cleaning rust of a bridge done clear
  C)
  Pressing fibres to make paper done clear
  D)
  Baking a cake done clear
  View Solution play_arrow

• question_answer64)
  On adding a few drops of dilute sulphuric acid to the blue vitriol (copper sulphate) solution, we get a blue coloured solution. When we drop a shaving blade into this blue coloured solution blue colour changes to green after sometime. Which type of change is illustrated by this activity?
  A)
  Physical change done clear
  B)
  Chemical change done clear
  C)
  Both of these done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer65)
  Choose the correct option on the basis of two statements (i) and (ii) (i) Hydrogen gas reacts with oxygen gas to form liquid water. (ii) Liquid water on evaporation changes to water vapour.
  A)
   (i) is a chemical change, (ii) is a physical change done clear
  B)
   (i) is a physical change, (ii) is a chemical change done clear
  C)
  Both (i) and (ii) are physical changes done clear
  D)
  Both (i) and (ii) are chemical changes done clear
  View Solution play_arrow

• question_answer66)
  In neutralization reaction acid reacts with a base to form salt and water and a lot of heat energy is given out. This reaction is:
  A)
  an exothermic physical change done clear
  B)
  an endothermic chemical change done clear
  C)
  an exothermic chemical change done clear
  D)
  an endothermic physical change done clear
  View Solution play_arrow

• question_answer67)
  Surface of a reactive metal may be attacked by air, water or other substances causing corrosion. Corrosion of iron is called rusting. The product formed by rusting is:
  A)
  rust                              done clear
  B)
  a brown solid done clear
  C)
  Both of these     done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer68)
  Anaerobic bacteria digest animal waste and produce biogas (Changed A). The biogas is then burnt as fuel (Change B). The following statements are related to these changes. Choose the correct one.
  A)
  A is a chemical change whereas B is a physical change. done clear
  B)
  5 is a chemical change whereas A is a physical change. done clear
  C)
  Both A and 5 are physical changes. done clear
  D)
  Both A and B are chemical changes. done clear
  View Solution play_arrow

• question_answer69)
  A metal when left exposed to the atmosphere for some time gets coated with green basic carbonate. The metal in question is
  A)
  Copper           done clear
  B)
  Nickel done clear
  C)
  Silver                           done clear
  D)
  Zinc done clear
  View Solution play_arrow

• question_answer70)
  Two changes are stated below: (i) A piece of magnesium gives of bright flames when burnt. (ii) A piece of iron glows red when heated strongly. Which of the above changes is a physical change?
  A)
   i only              done clear
  B)
   ii only done clear
  C)
  Both i and ii                 done clear
  D)
  neither i nor ii done clear
  View Solution play_arrow

• question_answer71)
  Some pieces of chalk were taken and mixed with water. In this change, how many new substances are formed?
  A)
  1 done clear
  B)
  2 done clear
  C)
  3 done clear
  D)
  No new substances is formed done clear
  View Solution play_arrow

• question_answer72)
  In a pressure-kerosene stove (i) We pump kerosene and convert it into vapours. (ii) The vapours are then ignited. Which of the following option is correct about the above statements?
  A)
   (i) is a chemical change; (ii) is a physical change. done clear
  B)
   (i) is a physical change; (ii) is a chemical change. done clear
  C)
   (i) and (ii) both are physical changes done clear
  D)
   (i) and (ii) both are chemical changes done clear
  View Solution play_arrow

• question_answer73)
  On the basis of reactions given below Acetic acid + Sodium hydrogen carbonate \[\to \](i) (i)\[\text{+Ca(OH}{{\text{)}}_{\text{2}}}\to \text{(ii)+water}\] (i) and (ii) will be?
  A)
   \[\text{(i)}\,\text{CaC}{{\text{O}}_{\text{3}}}\text{;}\,\text{(ii)}\,\text{C}{{\text{O}}_{\text{2}}}\] done clear
  B)
   \[\text{(i) }{{\text{H}}_{\text{2}}}\text{O;}\,\text{(ii)}\,\text{CaC}{{\text{O}}_{\text{3}}}\] done clear
  C)
   \[\text{(i) C}{{\text{O}}_{\text{2}}};\,(\text{ii})\,\text{CaC}{{\text{O}}_{\text{3}}}\] done clear
  D)
   \[\text{(i)}\,{{\text{H}}_{\text{2}}}\text{O;}\,\,\text{(ii)}\,\text{C}{{\text{O}}_{\text{2}}}\] done clear
  View Solution play_arrow

• question_answer74)
  Which of the following statement is correct?
  A)
  Burning of coal does not produce a new substance. done clear
  B)
  Rust is hydrated \[\text{F}{{\text{e}}_{\text{2}}}{{\text{O}}_{\text{3}}}\text{.}\] done clear
  C)
  The fizz that comes out when a soda bottle is opened is due to a chemical change. done clear
  D)
  Respiration is a physical process. done clear
  View Solution play_arrow

• question_answer75)
  Which of the following statement is true about chemical equation?
  A)
  Mass is conserved done clear
  B)
  Atoms are conserved done clear
  C)
  Mass as well as atoms are conserved done clear
  D)
  Molecules are conserved done clear
  View Solution play_arrow

• question_answer76)
  Pollution of air is a
  A)
  chemical change          done clear
  B)
  physical change done clear
  C)
  None of (a) or (b)        done clear
  D)
  Both (a) and (b) done clear
  View Solution play_arrow

• question_answer77)
  Which of the following is the chemical name of blue vitriol (neela thotha)?
  A)
  Sulphuric acid done clear
  B)
  Calcium carbonate done clear
  C)
  Copper sulphate done clear
  D)
  Zinc sulphate done clear
  View Solution play_arrow

• question_answer78)
  We mm on a bulb and filament changes its colour and becomes bright. Is it chemical change like burning?
  A)
  No, filament bum itself but that is not chemical change done clear
  B)
  Yes, filament bums itself like wood to give light done clear
  C)
  No, filament does not change into something new done clear
  D)
  Yes, filament made up of tungsten changes to its oxide on burning done clear
  View Solution play_arrow

• question_answer79)
  Brown colour of the apple after cutting is a
  A)
  Chemical change         done clear
  B)
  biological change done clear
  C)
  Physical change           done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer80)
  For protection of iron pipes from corrosion they are coated with
  A)
  Silver              done clear
  B)
  Copper done clear
  C)
  Aluminum                    done clear
  D)
  Zinc done clear
  View Solution play_arrow

• question_answer81)
  Which of the following is the name of the process of obtaining salt by evaporation of sea water?
  A)
  Amalgamation             done clear
  B)
  Sublimation done clear
  C)
  Crystallization    done clear
  D)
  Galvanization done clear
  View Solution play_arrow

• question_answer82)
  Blacksmith grinds edges of iron axe against a spinning wheel to sharpen it. Sparks of fire and heat is generated. On the basis of this statement choose the correct answer.
  A)
  It is a physical change as only shape of axe changes. done clear
  B)
  It is a chemical change as heat is generated. done clear
  C)
  It is chemical change as iron turns into new metal. done clear
  D)
  None of these. done clear
  View Solution play_arrow

• question_answer83)
  Magnesium ribbon bums in candle flame with
  A)
  brilliant green light       done clear
  B)
  brilliant white light done clear
  C)
  brilliant red light           done clear
  D)
  brilliant yellow light done clear
  View Solution play_arrow

• question_answer84)
  Read the given statements and choose the correct option. (I) Iron and sulphur are mixed to form a black and yellow mixture. (II) Mixture of iron and sulphur is heated to form a non-magnetic shiny grey substance.
  A)
  (I) is a chemical change done clear
  B)
  (II) is a physical change done clear
  C)
  Both are chemical changes done clear
  D)
  (I) is a physical change and (K) is a chemical change done clear
  View Solution play_arrow

• question_answer85)
  When carbon dioxide is passed through lime water, it turns milky due to two formation of
  A)
  Calcium hydroxide done clear
  B)
  Sodium hydrogen carbonate done clear
  C)
  Calcium carbonate done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer86)
  Directions: Match Column-I with Column-II and select the correct answer using the codes given below the columns.  

  Column - I	Column - II
  (A) Magnesium burnt in air	(p) Powdery ash is formed
  (B) Iron reacts with copper sulphate solution	(q) Color changes from blue to green
  (C) Coal is burnt in air	(r) \[\text{C}{{\text{O}}_{\text{2}}}\]is formed
  (D) Photosynthesis	(s) \[\text{C}{{\text{O}}_{\text{2}}}\]is used

  A)
  (A) \[\to \] (p), (B) \[\to \] (q), (C) \[\to \] (r), (D) \[\to \] (s) done clear
  B)
  (A) \[\to \] (q), (B) \[\to \] (p), (C) \[\to \] (r), (D) \[\to \] (s) done clear
  C)
  (A) \[\to \] (q), (B) \[\to \] (p), (C) \[\to \] (s), (D) \[\to \] (r) done clear
  D)
  (A) \[\to \] (p), (B) \[\to \] (q), (C) \[\to \] (s), (D) \[\to \] (r) done clear
  View Solution play_arrow

• question_answer87)
  Directions: Match Column-I with Column-II and select the correct answer using the codes given below the columns.

  Column - I	Column - II
  (A) The metal deposited on iron nails when they are dipped in the solution of copper sulphate.	(p) Rusting
  (B) The substance/crust which gets deposited on an iron pan when left in moist air.	(q) Copper
  (C) The process which converts iron to iron oxide in the presence of moisture and air.	(r) Galvanization
  (D) Coating an iron sheet with a layer of zinc.	(s) Rust

  A)
  (A) \[\to \] (q), (B) \[\to \] (s), (C) \[\to \] (p), (D) \[\to \] (r) done clear
  B)
  (A) \[\to \] (r), (B) \[\to \] (s), (C) \[\to \] (p), (D) \[\to \] (q) done clear
  C)
  (A) \[\to \] (q), (B) \[\to \] (p), (C) \[\to \] (s), (D) \[\to \] (r) done clear
  D)
  (A) \[\to \] (s), (B) \[\to \] (q), (C) \[\to \] (p), (D) \[\to \] (r) done clear
  View Solution play_arrow

• question_answer88)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 A change in which two or more substances (reactants) combine to produce one or more new substances (products) that has/have different chemical properties than the reactants is called chemical change. In a chemical change new products are formed. The characteristics of a chemical change are following: 1. Heat, light or any other radiation (ultraviolet) may be given off or absorbed. 2. Sound may be produced. 3. A change in smell may take place or a new smell may be given off. 4. A colour change may take place. 5. A gas may be formed. Change in which only physical properties of any substances get changed and no new substance is formed is called a physical change. Such as shape, size, colour and state, is known as physical change. A physical change is mostly reversible and during physical change no new substances are formed. Which of the following occurs during a chemical change?
  A)
  Exchange of heat         done clear
  B)
  Change of smell done clear
  C)
  Change of taste            done clear
  D)
  All of these done clear
  View Solution play_arrow

• question_answer89)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 A change in which two or more substances (reactants) combine to produce one or more new substances (products) that has/have different chemical properties than the reactants is called chemical change. In a chemical change new products are formed. The characteristics of a chemical change are following: 1. Heat, light or any other radiation (ultraviolet) may be given off or absorbed. 2. Sound may be produced. 3. A change in smell may take place or a new smell may be given off. 4. A colour change may take place. 5. A gas may be formed. Change in which only physical properties of any substances get changed and no new substance is formed is called a physical change. Such as shape, size, colour and state, is known as physical change. A physical change is mostly reversible and during physical change no new substances are formed. When we add sugar to water, it becomes sweet. Which of the following statements is TRUE regarding this change?
  A)
  It is a chemical change because a new substance is formed done clear
  B)
  It is a chemical change because there is exchange of heat. done clear
  C)
  It is a physical change because the original substance can be recovered. done clear
  D)
  It is a chemical change because there is only change in colour. done clear
  View Solution play_arrow

• question_answer90)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 A change in which two or more substances (reactants) combine to produce one or more new substances (products) that has/have different chemical properties than the reactants is called chemical change. In a chemical change new products are formed. The characteristics of a chemical change are following: 1. Heat, light or any other radiation (ultraviolet) may be given off or absorbed. 2. Sound may be produced. 3. A change in smell may take place or a new smell may be given off. 4. A colour change may take place. 5. A gas may be formed. Change in which only physical properties of any substances get changed and no new substance is formed is called a physical change. Such as shape, size, colour and state, is known as physical change. A physical change is mostly reversible and during physical change no new substances are formed. Which of the following statements is not correct?
  A)
  In a chemical change, colour of the object may change. done clear
  B)
  In a chemical change, heat will always be released. done clear
  C)
  A chemical change always involves physical change. done clear
  D)
  Rusting of iron becomes faster when humidity is high. done clear
  View Solution play_arrow

• question_answer91)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 A change in which two or more substances (reactants) combine to produce one or more new substances (products) that has/have different chemical properties than the reactants is called chemical change. In a chemical change new products are formed. The characteristics of a chemical change are following: 1. Heat, light or any other radiation (ultraviolet) may be given off or absorbed. 2. Sound may be produced. 3. A change in smell may take place or a new smell may be given off. 4. A colour change may take place. 5. A gas may be formed. Change in which only physical properties of any substances get changed and no new substance is formed is called a physical change. Such as shape, size, colour and state, is known as physical change. A physical change is mostly reversible and during physical change no new substances are formed. Which of the following is a chemical change?
  A)
  Foul smell comes when food gets spoiled done clear
  B)
  Pollution of air due to explosion of fire-work. done clear
  C)
  Change in colour of a cut apple if left outside. done clear
  D)
  All of the above. done clear
  View Solution play_arrow

• question_answer92)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 A change in which two or more substances (reactants) combine to produce one or more new substances (products) that has/have different chemical properties than the reactants is called chemical change. In a chemical change new products are formed. The characteristics of a chemical change are following: 1. Heat, light or any other radiation (ultraviolet) may be given off or absorbed. 2. Sound may be produced. 3. A change in smell may take place or a new smell may be given off. 4. A colour change may take place. 5. A gas may be formed. Change in which only physical properties of any substances get changed and no new substance is formed is called a physical change. Such as shape, size, colour and state, is known as physical change. A physical change is mostly reversible and during physical change no new substances are formed. The reason for a physical change to be named as such is that the
  A)
  change occurs only in physical properties done clear
  B)
  transfer of energy occurs done clear
  C)
  is a reversible change done clear
  D)
  All the above are correct done clear
  View Solution play_arrow

• question_answer93)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 A change in which two or more substances (reactants) combine to produce one or more new substances (products) that has/have different chemical properties than the reactants is called chemical change. In a chemical change new products are formed. The characteristics of a chemical change are following: 1. Heat, light or any other radiation (ultraviolet) may be given off or absorbed. 2. Sound may be produced. 3. A change in smell may take place or a new smell may be given off. 4. A colour change may take place. 5. A gas may be formed. Change in which only physical properties of any substances get changed and no new substance is formed is called a physical change. Such as shape, size, colour and state, is known as physical change. A physical change is mostly reversible and during physical change no new substances are formed. A change is considered as a chemical change when
  A)
  it is accompanied by energy change done clear
  B)
  it is accompanied by formation of new substances done clear
  C)
  it is accompanied by change in physical properties done clear
  D)
  All the above are correct done clear
  View Solution play_arrow

• question_answer94)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 2 Look at the following diagram and answer the given questions. Which type of change is shown in the above diagram?
  A)
  Chemical change   done clear
  B)
  Physical change done clear
  C)
  Reversible change  done clear
  D)
  Both (a) and (b) done clear
  View Solution play_arrow

• question_answer95)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 2 Look at the following diagram and answer the given questions. Above shown process will be faster in which area?    
  A)
  Hilly area                     done clear
  B)
  Desert area done clear
  C)
  Coastal area done clear
  D)
  Equally faster in all areas done clear
  View Solution play_arrow

• question_answer96)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 2 Look at the following diagram and answer the given questions. Which of the following is the prevention method for the process shown in the given diagram?
  A)
  Painting iron door done clear
  B)
  Coating of iron pipes with zinc metal done clear
  C)
  Greasing of metal surface done clear
  D)
  All of these done clear
  View Solution play_arrow

• question_answer97)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Change of water from liquid to steam on heating is a physical change. Reason (R): The volume during heating remains the same and the change involves a change in composition.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer98)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Evolution of gas is confirmed sign of physical change. Reason (R): Hydrogen gas is evolved on reaction of acids on metals.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer99)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Blue color of copper sulphate solution changes on addition of piece of zinc. Reason (R): Zinc is above copper in activity series
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer100)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Breaking of a bone china plate is a physical change. Reason (R): When a bone china plate breaks, the pieces cannot be joined to get back the original plate.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer101)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Respiration is an exothermic process. Reason (R): In an exothermic process heat is evolved.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer102)
  DIRECTIONS: The questions in this segment consists of two statements, one labelled as "Assertion A" and the other labelled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Conversion of oxygen to ozone is a chemical change. Reason (R): Ozone acts as a protective shield and protects us from harmful radiation of the sun.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer103)
  DIRECTIONS: Read the following three statements and choose the correct answer. (i) A few drops of petrol poured on to your palm will feel cool, because it involves evolution of heat. (ii) Burning of a petrol is an exothermic reaction. (iii) Neutralization reaction is an endothermic change.
  A)
  Statement (i) and (iii) are incorrect but (ii) is correct done clear
  B)
  Statement (i) and (ii) are incorrect but (iii) is correct done clear
  C)
  All statements are correct done clear
  D)
  All statements are incorrect done clear
  View Solution play_arrow

• question_answer104)
  DIRECTIONS: Read the following three statements and choose the correct answer. (i) Cooking of rice is a physical change. (ii) Pasteurization of milk is a chemical change (iii) Iron pipes coated with zinc do not get rusted easily
  A)
  Statement (i) and (iii) are incorrect but (ii) is correct done clear
  B)
  Statement (i) and (ii) are incorrect but (iii) is correct done clear
  C)
  All statements are correct done clear
  D)
  All statements are incorrect done clear
  View Solution play_arrow

• question_answer105)
  DIRECTIONS: Read the following three statements and choose the correct answer. (i) Burning of magnesium ribbon is an endothermic reaction. (ii) Magnesium on burning in air forms ash. (iii) Ash formed on burning of magnesium ribbon is magnesium dioxide.
  A)
  Statement (i) and (iii) are incorrect but (ii) is correct done clear
  B)
  Statement (i) and (ii) are incorrect but (iii) is correct done clear
  C)
  All statements are correct done clear
  D)
  All statements are incorrect done clear
  View Solution play_arrow

• question_answer106)
  DIRECTIONS: On the basis of following diagram/picture answer the questions given below: In an experiment a painted iron nail was placed into a beaker containing sea water (Fig 'A'). The beaker was left undisturbed for about 10 days. After 10 days, the nail began to rust (Fig 'B') which of the following statements is/are correct?               (i) Poor quality paint was used to paint iron nail. (ii) Oxygen and water cause rusting. (iii) Presence of salts in sea water enables rust formation faster.
  A)
   (i) only                        done clear
  B)
   (ii) only done clear
  C)
   (iii) only         done clear
  D)
   (ii) and (iii) done clear
  View Solution play_arrow

• question_answer107)
  DIRECTIONS: On the basis of following diagram/picture answer the questions given below: The four diagrams below represents the results of mixing atoms of different substances. Each atom is represented by a different symbol. Which diagram correctly shows a chemical change?
  A)
  done clear
  B)
  done clear
  C)
  done clear
  D)
  done clear
  View Solution play_arrow

• question_answer108)
  DIRECTIONS: On the basis of following diagram/picture answer the questions given below: Three substances given below are kept in the open for a few days and some changes were observed. Which of the substances will show chemical changes?
  A)
  Eggs done clear
  B)
  Plastic bottle done clear
  C)
  Both eggs & moth balls done clear
  D)
  All eggs, plastic bottle and moth balls done clear
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• question_answer109)
  DIRECTIONS: On the basis of following diagram/picture answer the questions given below: Which of the following Venn diagrams shows the relationship between changes correctly?
  A)
         done clear
  B)
  done clear
  C)
         done clear
  D)
  done clear
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• question_answer110)
  DIRECTIONS: On the basis of following diagram/picture answer the questions given below: What causes the candle flame to get extinguished?
  A)
  Evolution of \[{{\text{O}}_{\text{2}}}\] gas done clear
  B)
  Evolution of \[\text{C}{{\text{O}}_{\text{2}}}\] gas done clear
  C)
  Formation of \[\text{Ca}{{\left( \text{OH} \right)}_{\text{2}}}\] done clear
  D)
  Formation of \[\text{CaC}{{\text{l}}_{\text{2}}}\] done clear
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• question_answer111)
  DIRECTIONS: On the basis of following diagram/picture answer the questions given below: Which portion of a ship shown below will rust the fastest?
  A)
  A done clear
  B)
  B and C done clear
  C)
  C done clear
  D)
  A, B and C will get rust equally done clear
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• question_answer112)
  The diagram below shows the formation of two water molecules How many atoms combined to form the two water molecules?
  A)
  Total 6, two oxygen and four hydrogen atoms done clear
  B)
  Total 6, two hydrogen and four oxygen atoms done clear
  C)
  Total 6, three oxygen and three hydrogen atoms done clear
  D)
  Total 10, six hydrogen and four oxygen Atoms done clear
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