Acid base and salt part 2

Acid base and salt part 2

1. What is the colour of litmus in a solution of ammonium hydroxide?
2. Two solutions A and B have pH values of 5 and 8 respectively. Which solution will be basic in nature?                                            
3. On adding dilute hydrochloric acid to copper oxide powder, the solution formed is blue green, predict the new compound formed which imparts a blue green colour to the solution. 
4. How does the flow of acid rainwater into a river make the survival of aquatic life in the river difficult?                                             
5. Write chemical equations to show the reactions taking place when a glass rod dipped in concentrated hydrochloric acid is introduced in a jar containing ammonia gas.                                                   
6. Which acid is present in sour milk or curd?
7. Which acid is present in tamarind?
8. What is aqua regia?
9. Which chemical is present in enamel?
10. Do alkalis also react with metals? Give one example
11. A yellow colour solution turns reddish pink in acidic solution and remains as such in basic solution. What do you call such substances?
12. Two solutions have pH numbers 7 and 2 respectively. Which solution has more H concentration?
13. How is the concentration of hydronium ion (H₃O⁺) affected when a solution of an acid is diluted?
14. Tooth enamel is one of the hardest substances in our body. How does it undergo damage due to eating chocolates and sweets? How do tooth pastes prevent this damage?             
15. A compound which is prepared from gypsum has the property of hardening when mixed with a proper quantity of water. Identify the compound. Write the chemical equation for its preparation. For what purpose is it used in hospitals?                           
16. What is meant by water of crystallisation, of a substance? Describe an activity to show that blue copper sulphate crystals contain water of crystallisation.                                                    
17. A compound X of sodium is commonly used in kitchen for making crispy pakoras. It is also used for curing acidity.
18. What is Baking powder? How does it make the cake soft and spongy? 
19. Write the chemical formula for washing soda. How may it be obtained from baking soda? Name an industrial use of washing soda other than washing clothes.                                  
20. Write the chemical formula for bleaching powder. How is bleaching powder prepared? For what purpose is it used in paper factories?