Chemistry Past Questions and Answers

If the rate of diffusion of oxygen gas is taken as 1, what will be rated of diffusion of methane whose relative molar mass is 16?

A 2.0
B 1.8
C 1.4
D 1.0
E 0.5

Question 272:

If the temperature of a gas is increased?

A The kinetic energy of the emolecules will decrease
B The pressure will decrease if the volume is constant
C The gas will occupy a greater volume if the pressure is constant
D The mass of the gas will decrease
E The pressure and volume will increase

Question 273:

When a little brine was added to a metal nitrate a white precipitate was formed which first turned violet and then black on exposure to ai. The metal nitrate is therefore?

A Sodium nitrate
B Mercuric nitrate
C Lithium nitrate
D Silver nitrate
E Potassium nitrate

Question 274:

If atom X with six electrons in its outermost shell combines with atom Y with one electron in its outermost shell to form an ionic compound, then?

A Six atoms of X will combine with one of Y
B Two atoms of X will combine with six of Y
C One atom of X will combine with two of Y
D Two atoms of X will combine with one of Y
E One atom of X will combine with six of Y

Question 275:

The nitrogen gas obtained by burning an excess of phosphorus in air has a density higher than the nitrogen from nitrogen compounds because the nitrogen from air is contaminated with?

A Some unburnt phosporus
B P<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>5</sub> vapour
C Some oxygen
D Rare gases
E Carbondioxide