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.
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.
2NH4Cl +Ca(OH)2 --> CaCl2 +2NH3 +2H2O