CHEMISTRY ASSIGNMENT
5. (a) Name one product of the destructive distillation of coal that is (i) solid (ii)
liquid (iii) gas (3marks)
(b) (i) what is the major component of synthesis gas(ii) name two allotropes
of carbon that are (i) crystalline
(ii) amorphous (5 marks)
( c )(i) give the reason why copper turnings dissolve in AgNO3 solution but
remain insoluble in Pb(NO3)2 solution.
(4 marks)
(ii) Mention three types of salt (3 marks)
(d) (i) list three chemical properties of acids (3marks)
(ii) give two large-scale use of HNO3 (2 marks)
(iii) state what will be observed if a damp blue litmus paper is dropped into a
gas jar of chlorine (2 marks)
(iv) Give one test to identify ammonia in the laboratory (2 marks)
(v) state the role of alum in water purification (1 mark)
Answer to No. 5
(a) (i) coke (ii) ammoniacal liquor (iii) coal gas
(b) (i) methane (ii) (i) diamond and graphite (ii) charcoal and coal
(c) (i) Copper is higher in the electrochemical series than silver. Hence it will
displace silver ions from the solution. Copper, being less reactive than lead
cannot displace lead, hence it remains insoluble in Pb(NO3)2(aq).
(ii) basic salt, neutral salt, and double salt
(d) (i) 1. Acids react with metals to form salts and liberate hydrogen gas.
1. Acids react with bases to form salts and water, which is also known as a
neutralization reaction.
2. Acids react with trioxocarbonates (IV) to liberate carbon dioxide.
(ii) 1. production of ammonium nitrate, a major component of fertilizers.
2. Nitric acid is used as a rocket propellant in the aerospace industry.
(iii) The blue colour will turn to red and then to white. Chlorine gas reacts
with water to produce an acidic solution which is also an effective bleach.
(iv) Ammonia gas reacts with Hydrochloric acid to form dense white fumes of
Ammonium chloride.
(v) Alum is added to water to destabilize the mud particles suspended in it. This
process is known as coagulation. Alum helps in purifying water by aluminium
which coagulates the mud particles. Because of the high charge on the aluminium
ion (Al3+), it helps the small particles of suspended solids to group together until
they are of such size that they sink and can be removed.