Chemistry
Solution P has a pH of 13, solution Q has a pH of 6 and solution R has a pH of 2.
Which solution:
(a) Will liberate ammonia from ammonium sulphate on heating.
(b) is a strong acid?
(c) contains molecules as well as ions?
Answer
(a) Solution P
Reason — When alkalis are warmed with an ammonia salt, ammonia gas is given out.
(b) Solution R
Reason — Number 2 on pH scale represents a strong acid.
(c) Solution Q
Reason — As Q with pH 6 is a weak acid and will not be able to completely dissociate into ions. Hence, will have molecules and ions both.
Related Questions
When you use a universal indicator, you see that solutions of different acids produce different colours. Indeed, solutions of the same acid with different concentrations will also give different colours. Why?
You are supplied with five solutions : A, B, C, D and E with pH values as follows:
A = 1.8, B = 7, C = 8.5, D = 13, and E = 5
Classify these solutions as neutral, slightly or strongly acidic and slightly or strongly alkaline.
Which solution would be most likely to liberate hydrogen with:
(a) magnesium powder
(b) powdered zinc metal. Give a word equation for each reaction.
Define the following and give two examples in each case : (a) a normal salt, (b) an acid salt, (c) a basic salt.
Answer the following questions related to salts and their preparations:
(a) What is a 'salt' ?
(b) What kind of salt is prepared by precipitation?
(c) Name a salt prepared by direct combination. Write an equation for the reaction that takes place in preparing the salt you have named.
(d) Name the procedure used to prepare a sodium salt such as sodium sulphate.