A solid ball of metal has a spherical cavity inside it. If the ball is heated, the volume of the cavity will

(a) Increase

(b) Decrease

(c) Remain unaffected

(d) Have its shape changed

Submitted By: Syed Bilawal Shah (Sain)

Nitrogen is prepared in the laboratory by heating

(a) Ammonium sulphate

(b) Aluminium nitrate

(c) The mixture of ammonium chloride and sodium nitrite

(d) The mixture of ammonium chloride and calcium oxide

Submitted By: Syed Bilawal Shah (Sain)

Which one of the following represents a chemical change?

(a) Evaporation of alcohol

(b) Sublimation of iodine

(c) Heating a platinum wire in a bunsen flame

(d) Heating of mercuric oxide powder

Submitted By: Syed Bilawal Shah (Sain)

A thermostat is

(a) An instrument by which the accuracy of thermometers is determined

(b) A modern type of thermos flask which works on the principle of equipartition of heat energy

(c) A device used to maintain a constant temperature of a water bath or an oven

(d) A device that varies the temperature of a bath

Submitted By: Syed Bilawal Shah (Sain)