CBSE Guess > Papers > Important Questions > Class X > 2008 > Science > Science By :- Nagesh Kumar

Science - Acid Bases and Salts

1. A metal compound ‘X’ reacts with dilute hydrochloric acid to produce gas (Y). The gas (Y) evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride. Write names of x & y. 
2. Why does distilled water not conduct electricity, whereas rainwater does?    
3.  Fresh milk has a pH 6. How do you think the pH will change as it becomes sour?
4. Name the acid found in (a) Soft drinks (b) Vinegar.
5. How does an acid taste?
6. Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas?
7. What are acid & base indicators?
8. What are alkalis?
9. Why does an aqueous solution of acid conduct electricity?
10. Write an equation to show the reaction between Plaster of Paris and water.
11. Name the sodium compound which is used for softening hard water.
12. Name three mineral acids.
13. How is concentration of hydroxide ions (OH-) affected when excess of base is dissolved in a solution of sodium hydroxide?
14. What is bleaching powder? How is it prepared? Write chemical equation involved in the preparation of bleaching powder. Write two uses of bleaching powder.
15. What is the chemical name of washing soda?
16. What is a base?
17. What is an alkali?
18. Define pH.
19. What is an indicator?