done 7th Acids, Bases and Salts

• question_answer1)
  In the given table, identify among the given substances having the same taste.  

  Substance	Taste (sour/ bitter/ any other)
  Lemon juice
  Orange juice
  Vinegar
  Curd
  Tamarind (imli)
  Sugar
  Common salt
  Amla
  Baking soda
  Grapes
  Unripe mango

   
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• question_answer2)
  Check the effect of given substances on turmeric solution and also remark.  

  Substance	Effect on turmeric solution	Remarks
  Lemon juice
  Orange juice
  Vinegar
  Milk of magnesia
  Baking soda
  Lime water
  Sugar
  Common Salt

   
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• question_answer3)
  What is acid rain? Where do these acids come from? What is the effect of acid rain?
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• question_answer4)
  Why acids and bases should be handled in laboratory very carefully?
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• question_answer5)
  State differences between acids and bases.
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• question_answer6)
  Ammonia is found in many household products such as window cleaners. It turns red litmus to blue. What is its nature?
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• question_answer7)
  Name the source from which litmus solution is obtained. What is the use of this solution?
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• question_answer8)
  Is the distilled water acidic/basic/neutral? How would you verify it?
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• question_answer9)
  Describe the process of neutralization with the help of an example.
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• question_answer10)
  State whether the following statements are true or false and correct the false statements. (a) Nitric acid turns red litmus to blue. (b) Sodium hydroxide turns blue litmus to red. (c) Sodium hydroxide and hydrochloric acid neutralizes each other and form salt and water. (d) Indicator is a substance which shows different colours in acidic and basic solutions. (e) Tooth decay is caused by the presence of a base.  
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• question_answer11)
  Dorji has a few bottles of soft drink in his restaurant. But unfortunately, these are not labelled. He has to serve the drinks on the demand of customers. One customer wants acidic drink, another wants basic and third one wants neutral drink. How will Dorji decide which drink is to be served to whom?
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• question_answer12)
  Explain why (a) an antacid tablet is taken when you suffer from acidity. (b) calamine solution is applied on the skin, when an ant bites. (c) factory waste is neutralized before disposing it into the water bodies.  
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• question_answer13)
  Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and third is a sugar solution. How will you identify them? You have only turmeric indicator.
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• question_answer14)
  Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.
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• question_answer15)
  Consider the following statements : (i) Both acids and bases change colour of all indicators. (ii) If an indicator gives a colour change with an acid, it does not give a change with a base. (iii) If an indicator changes colour with a base, it does not change colour with an acid. (iv) Change of colour with an acid and a base depends on the type of the indicator. Which of the above statements is/are correct? (a) Only (iv) (b) (i) and (iv) (c) (ii) and (iii) (d) All of these  
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