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ACIDS, BASES AND SALTS

 

1.  Why is Plaster of Paris stored in a moisture proof container?
2.  What do you mean by neutralization reaction? Give two examples.
3.  Mention two uses of baking soda and washing soda.
4.  Why does a milkman add a small amount of baking soda to fresh milk to shift the pH of fresh milk from 6 to slightly alkaline?
5.  Why do acids not show acidic behavior in the absence of water?
6.  Rain water conducts electricity but distilled water does not. Why?
7.  Why don’t we keep sour substances in brass and copper vessels?
8.  What is the common name of CaOCl2?
9.  Name the compound used for softening hard water.
10.  What happens when baking soda is heated?
11.  Give the properties and uses of bleaching powder.
12.  Give a few uses of acids, bases and salts respectively.

1.  How will you test for a gas which is liberated when HCL reacts with an active metal?      (CBSE 2008)
2.  What is baking powder? How does it make the cake soft and spongy?      (CBSE 2008)
3.  When fresh milk is changed into curd will its pH value increase or decrease? Why?
4.  Give Arrhenius definition of an acid and a base.      (CBSE 2009)
5.  What happens chemically when quick lime is added to water?      (CBSE 2008)
6.  Name the gas evolved when dilute HCL reacts with Sodium hydrogen carbonate. How is it recognized?      (CBSE 2008)
7.  How does the flow of acid rain water into a river make the survival of aquatic life in the river difficult?      (CBSE 2008)
8.  How is the pH of a solution of an acid influenced when it is diluted?      (CBSE 2008 F)
9.  How does the pH of the solution change when a solution of base is diluted?      (CBSE 2008 F)
10.  Arrange these in increasing order of their pH values- NaOH, blood, lemon juice.      (CBSE 2008 F)
11.  Two solutions of A and B have pH values of 5 and 8. Which solution will be basic in nature?      (CBSE 2008 C)
12.  Why does tooth decay start when pH of mouth is lower than 5.5?      (CBSE 2009)
13.  What would be the colour of litmus in a solution of sodium carbonate?      (CBSE 2009)
14.  Name the products obtained when sodium hydrogen carbonate is heated. Write the chemical equation for the same.      (AI CBSE 2009)
15.  Write the chemical formula of washing soda and baking soda. Which one of these two is an ingredient of antacids? How does it provide relief in stomachache?      (CBSE 2008 F)
16.  What do you mean by �water of crystallization� of a substance? Describe an activity to show that blue copper sulphate crystals contain water of crystallization.      (CBSE 2009 F)
17.  How can washing soda be obtained from baking soda? Name an industrial use of washing soda other than washing clothes.      (AI CBSE 2008)
18.  Why does 1 M HCL solutions have a higher concentration of H+ ions than 1M CH3COOH solution?      (AI CBSE 2009)

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