Chemistry Past Questions and Answers

The products of the combustion of candle wax are

A Hydrogen and water
B Oxygen and water
C Carbon (IV) oxide and water
D Carbon (II) oxide and water

Question 22:

When 50cm² of a saturated solution of sugar of molar mass 342 g at 40^oC was evaporated to dryness, 34.2g of dry solid was obtained. The solubility of sugar at 40^oC is

A 2.0 mol dm^-3
B 3.5 mol dm^-3
C 7.0 mol dm^-3
D 10.0 mol dm^-3

Question 23:

Which of the following results in the fall of acid rain?

A Oxides of lead
B Particulate matter
C Oxides of sulphur
D Gaseous hydrocarbon

Question 24:

Water has the ability to dissolve almost all substance because its molecules has a structure with

A One positive end and one neutral end
B One positive end and one negative end
C Two negative ends
D Two positive ends

Question 25:

When a crystal was added to the clear solution of its salt, the crystal did not dissolve and the solution remained unchange. This showed that the solution was

A Supersaturated
B Concentrated
C Unsaturated
D Saturated