-
question_answer1)
In a pressure-kerosene stove,
(i) We pump kerosene and convert it into vapours. |
(ii) The vapours are then ignited. |
Which of the following is true 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)
Both (i) and (ii) are physical changes. done
clear
D)
Both (i) and (ii) are chemical changes. done
clear
View Solution play_arrow
-
question_answer2)
Which of the following statements is correct about the given changes?
(i) Drawing copper into a wire |
(ii) Breaking of a glass |
(iii) Heating an iron nail till red hot |
(iv) Inflating a basketball |
A)
(i) and (ii) are chemical changes while (iii) and (iv) are physical changes. done
clear
B)
(ii) and (iii) are chemical changes while (i) and (iv) are physical changes. done
clear
C)
All are physical changes. done
clear
D)
All are chemical changes. done
clear
View Solution play_arrow
-
question_answer3)
Vishakha took few wire pieces made up of different metals and placed them in blue solution of copper sulphate. What will be the changes in the colour of the solutions present in beakers I, II and III?
A)
B)
C)
D)
View Solution play_arrow
-
question_answer4)
Match column I with column II and select the correct option from the codes given below.
Column I | Column II |
(P) Expansion of metals on heating | (i) Neither physical nor chemical change |
(Q) A stone kept in the sunlight | (ii) Chemical change |
(R) Burning of a candle | (iii) Combination of physical and chemical changes |
(S) Curdling of milk | (iv) Physical change |
A)
B)
C)
D)
View Solution play_arrow
-
question_answer5)
Kanav took two test tubes marked as I and II. In test tube I, he put calcium carbonate and hydrochloric acid while in test tube II, he put zinc granules and hydrochloric acid. He passed the gas coming out from both the test tubes in lime water. What would be his observation?
A)
The gas coming out from test tube I turned lime water milky. done
clear
B)
The gas coming out from test tube II turned lime water milky. done
clear
C)
The gases coming out from both the test tubes turned lime water milky. done
clear
D)
None of these. done
clear
View Solution play_arrow
-
question_answer6)
Observe the given reaction sequence carefully.
Acetic acid + Sodium hydrogen carbonate \[\xrightarrow{{}}\](i)
|
\[(i)+Ca{{(OH)}_{2}}\xrightarrow{\,}\,(ii)+Water\]
|
What could (i) and (ii) be?
A)
B)
C)
D)
View Solution play_arrow
-
question_answer7)
The ash which is collected after burning of magnesium ribbon is dissolved in water to give a solution X. What is the nature of the solution X when it is tested with indicators?
A)
It turns blue litmus red and phenolphthalein pink, hence it is an acidic solution. done
clear
B)
It turns red litmus blue and phenolphthalein pink, hence it is a basic solution. done
clear
C)
It turns blue litmus red and gives no colour with phenolphthalein, hence it is an acidic solution. done
clear
D)
It does not change colour of red or blue litmus and phenolphthalein, hence it is a neutral solution. done
clear
View Solution play_arrow
-
question_answer8)
Fill in the blanks by choosing an appropriate option.
|
When sugar is dissolved in water, it undergoes a ___(i)___ change but if sugar is heated in a test tube over the Bunsen burner flame, it first melts, turns brown and finally turns ___(ii)___. The new substance formed is ___(iii)___ and the change is a ___(iv)___ change.
|
A)
B)
C)
D)
View Solution play_arrow
-
question_answer9)
Match column I with column II and select the correct option from the codes given below.
Column I
|
Column II
|
(P) Dipping iron sheets in molten zinc
|
(i) Alloying
|
(Q) Prevents the iron surface to come in contact with moisture
|
(ii) Galvanization
|
(R) Two or more metals are mixed in definite ratio to form a homogeneous mixture
|
(iii) Tinning
|
(S) Coating expensive utensils with tin
|
(iv) Painting
|
A)
B)
C)
D)
View Solution play_arrow
-
question_answer10)
Study the given figure carefully.
|
|
Which of the following reactions explains the above change most appropriately?
|
A)
\[ZnS{{O}_{4}}+Cu\to CuS{{O}_{4}}+Zn\] done
clear
B)
\[CuS{{O}_{4}}+Fe\to FeS{{O}_{4}}+Cu\] done
clear
C)
\[FeS{{O}_{4}}+Cu\to CuS{{O}_{4}}+Fe\] done
clear
D)
\[CuS{{O}_{4}}+Zn\to ZnS{{O}_{4}}+Cu\] done
clear
View Solution play_arrow
-
question_answer11)
Kirti kept a metal spoon in a glass jar filled with pickle for a few days. She observed that there were holes in the spoon. What could be the possible reason for this?
A)
Oil present in pickle dissolves the metal. done
clear
B)
Oil present in pickle liberates a gas in which metal gets dissolved. done
clear
C)
Metal reacts with acid present in pickle to form salt hence, metal gets dissolved. done
clear
D)
The glass reacts with metal to give acid which dissolves the metal. done
clear
View Solution play_arrow
-
question_answer12)
Which of the following do not represent that a chemical change is taking place?
I. A gas is produced. |
II. Precipitate is formed. |
III. State of a substance changes |
IV. A new odour is produced. |
V. Shape of a substance changes |
A)
I and V only done
clear
B)
I and IV only done
clear
C)
II, III and V only done
clear
D)
III and V only done
clear
View Solution play_arrow
-
question_answer13)
Observe the given reaction carefully and fill in the blanks by choosing an appropriate option.
\[F{{e}_{(s)}}+CuS{{O}_{4(aq)}}\to FeS{{O}_{4(aq)}}+C{{u}_{(s)}}\]
|
Before reaction, iron is ___(i)___ in colour and solution is ___(ii)___ in colour. After reaction iron gets ___(iii)___ deposits and the solution becomes ___(iv)___ in colour.
|
A)
B)
C)
D)
View Solution play_arrow
-
question_answer14)
Observe the given experimental set-up carefully.
|
|
In which test tubes rusting of iron nails will not take place?
|
A)
P and Q only done
clear
B)
Q and R only done
clear
C)
P and R only done
clear
D)
All of these done
clear
View Solution play_arrow
-
question_answer15)
Kunal took few iron turnings and mixed them well with sulphur powder. He could separate the iron turnings with the help of a magnet. He heated the mixture for some time and tried to separate the iron turnings with the magnet but he could not. Why?
A)
On heating, a chemical change takes place and a new compound is formed. done
clear
B)
On heating, iron becomes non-magnetic hence, it is not attracted by magnet. done
clear
C)
On heating, a physical change takes place hence iron and sulphur gets mixed up. done
clear
D)
On heating, iron evaporates and only sulphur is left behind. done
clear
View Solution play_arrow
-
question_answer16)
Observe the given figure carefully and identify the substances marked as (p), (q) and (r).
A)
B)
C)
D)
View Solution play_arrow
-
question_answer17)
Study the given Venn diagram carefully.
|
|
Identify 1, 2 and 3.
|
A)
B)
C)
D)
View Solution play_arrow
-
question_answer18)
A)
1 and 2 only done
clear
B)
2 and 3 only done
clear
C)
1, 4 and 5 only done
clear
D)
All of these. done
clear
View Solution play_arrow
-
question_answer19)
Read the given statements and select the correct option.
Statement 1: Many cut fruits, when kept in open turn brown. |
Statement 2: Browning of fruits is due to a chemical reaction. |
A)
Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1. done
clear
B)
Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1. done
clear
C)
Statement 1 is true and statement 2 is false. done
clear
D)
Both statements 1 and 2 are false. done
clear
View Solution play_arrow
-
question_answer20)
During the science activity, Ms Prabha demonstrated an experiment in following steps:
Step 1: She burned a substance X over the candle flame and white dazzling light was observed. Also white powdery ash was left behind. |
Step 2: She mixed the white ash formed with small amount of water. Then she dipped red and blue litmus papers into the solution one by one. |
Which of the following observations are correct?
I. The substance burned in step 1 was magnesium. |
II. The white ash formed in step 1 was magnesium oxide. |
III. The solution formed in step 2 was acidic in nature |
IV. The solution formed in step 2 turned blue litmus red. |
A)
I and II only done
clear
B)
III and IV only done
clear
C)
I, II and III only done
clear
D)
II, III and IV only done
clear
View Solution play_arrow