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

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

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

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

A particle that contains 11 protons, 12 neutrons and 10 electrons is probably a

A. neutral non-metal

B. metallic ion

C. non-metallic ion

D. neutral metal

A difference between chemical and physical change is that in a chemical change

A. oxygen is consumed

B. heat is supplied

C. a reversible process oocurs

D. a new substance is formed

The volume of 2.5 moles of oxygen at s.t.p is
[Molar volume of a gas at s.t.p = 22.4 dm³]

A. 50.0 dm³

B. 84.0 dm³

C. 28.0 dm³

D. 56.0 dm³

Nuclear fission involves the splitting of a heavy element into two nuclei of

A. nearly equal masses with a relaese of energy and radiaton

B. equal masses with a relaese of energy

C. equal masses with a release of energy and radiation

D. unequal masses without any relaese of energy

What is the molar mass of a substance, if 0.4 mole of the substance has a mass of 25.0g?

A. 62.5 g

B. 40.0 g

C. 6.3 g

D. 2.5 g

The element with the electron configuration 1s²2s²2p³ is

A. calcium

B. chlorine

C. oxygen

D. nitrogen