Chemistry Past Questions and Answers

Alkanes

A Are all gases
B Have the general formula CnH2n + 2O
C Contain only carbon and hydrogen
D Are usually soluble in water
E Are usually active compounds

Question 382:

If an excess of a liquid hydrocarbon is poured into a jar of chlorine, and the sealed jar is then exposed for several hours to bring sunlight, all the chlorine gas is consumed. The hydrocarbon is said to have undergone

A A polymerization reaction
B An isomerization reaction
C An addition reaction
D A substitution reaction
E A reduction reaction

Question 383:

The function of conc. H2SO4 in the esterification of ethanoic acid with ethanol is to

A Serve as a dehydrating agent
B Serve as a solvent
C Act as a catalyst
D Prevent any side reaction
E Serve as an oxidizing agent

Question 384:

A piece of sea shell, when dropped into a dilute solution of hydrochloric acid, produces a colourless, odourless gas which turns clear limewater milky. The sea shell contains

A Sodium chloride
B Ammonium nitrate
C Calcium carbonate
D Calcium chloride
E Magnesium chloride

Question 385:

Which of the following electrodes is used in electrolysis of bauxite (Al2O3) in molten cryolite?

A Steel electrodes
B Carbon electrodes
C Mercury electrodes
D Carbon anode and steel cathode
E Carbon cathode and stell anode