Q.1 (b) Choose the most appropriate answer for the following:

(iii) This is not an alloy:

A) brass

B) bronze

C) solder

D) Duralumin

 Give appropriate scientific reason for the following statement:

Zinc oxide is reduced to zinc by using carbon monoxide, but aluminium oxide cannot be reduced by a reducing agent.

For each of the substance listed below. Describe the role played in the extraction of aluminium.

(1) Cryolite: 

(2) sodium hydroxide

(3) Graphite

 Explain why:
(1) In the electrolysis of alumina using the Hall Heroult’s process the electrolyte.

(2) Iron sheets are coated with zinc during galvanization.

Identify the acid which matches the following description:

The acid which is used in the preparation of a non-volatile acid.

The acid on mixing with silver nitrate solution produces a white precipitate which is soluble in excess ammonium hydroxide ?

Q7. (a) The following question is pertaining to the laboratory preparation of hydrogen chloride gas:

(i) Write the equation for its preparation mentioning the condition required.

(ii) Name the drying agent used and justify your choice.

(iii) State a safety precaution you would take during the preparation of hydrochloric acid.

38.

 State one relevant observation for the following:
 when ammonia gas is burnt in an atmosphere of excess oxygen.

Given balanced chemical equation for each of the following:
Lab preparation of ammonia using an ammonium salt.

The reaction of ammonia with excess chlorine.