Question

3. Give a chemical test to distinguish between :
(a) dilute sulphuric acid and dilute hydrochloric acid,
(b) dilute sulphuric acid and conc. sulphuric acid.​

Answer 1

The reaction of barium chloride with dilute sulphuric acid forms white precipitate of barium sulphate and hydrochloric acid. This type of reaction is called double displacement reaction in which both the reactants exchange their partners.

BaCl2 (aq.)+ H2SO4 (aq.) ----- > BaSO4 (s) + 2HCl (aq.)

But when the barium chloride is treated with dilute nitric acid, all the reactants and products will be in aqueous state indicating that the complete solution will contain the ions of Ba+2 , Cl- , H+, NO3-

BaCl2 (aq.) + 2HNO3(aq.) ---- > Ba(NO3)2 (aq.) + 2HCl (aq.)

For a reaction to take place, either of the following conditions which must take place:

(a) the formation of insoluble product or precipitate.

(b) the evolution of gas.

(c) the formation of non-dissociating product.

Neither of these conditions is taking place on the reaction of barium chloride with dilute hydrochloric acid and nitric acid. hence, no reaction takes place in either of this case contrary to that of dilute sulphuric acid.

In case of reaction of barium chloride with dilute hydrochloric acid, the double displacement reaction cannot take place due to same anions with both the reactants.

BaCl2 (aq.)+ HCl (aq.) ----- > no reaction

Answer 2

Answer:

I don't know sry.................