Nitrogen obtained from the liquefaction of air has a higher density than that obtained from nitrogen containing compounds because the former contains

A. water vapour
B. oxygen
C. carbon (IV) oxide
D. rare gases

In order to remove one electron from a 3S orbital of gaseous sodium atom, about 496KJMol-1 of energy is required. This energy is referred to as
A. electron affinity
B. ionization energy
C. activation evergy
D. electronegativity

In which of the following are water molecules in the most disorderly arrangement?

A. Ice at -10°C
B. Ice at 0°C
C. Water at 100°C
D. Steam at 100°C

A gaseous metallic chloride MClx consists of 20.22% of M by mass. The formula of the chloride is?
[M = 27, Cl = 35.5]

A. MCl
B. MCl2
C. MCl3
D. M2Cl6

Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
From the equation above, the mass of magnesium required to react with 250cm3 of 0.5M HCl is
[Mg = 24]

A. 0.3g
B. 1.5g
C. 2.4g
D. 3.0g

Which of the following will have its mass increased when heated in air?
A. Helium
B. Magnesium
C. Copper pyrites
D. Glass

Which is the temperature of a given mass of a gas initially at 0°C and 9 atm, if the pressure is reduced to 3 atm at constant volume?
A. 91K
B. 182K
C. 273K
D. 819K

Which of the following gases will diffuse fastest when passed through a porous plug?
[H = 1, C = 12, N = 14, O = 16]
A. Propane
B. Oxygen
C. Methane
D. Ammonia

56.00cm3 of a gas at S.T.P. weighed 0.11g. What is the vapour density of the gas?
[Molar volume of a gas at S.T.P = 22.4dm3]
A. 11.00
B. 22.00
C. 33.00
D. 44.00

200cm3 each of 0.1M solutions of lead (II) trioxonitrate(V) and hydrochloric acid were mixed. Assuming that lead (II) chloride is completely insoluble, calculate the mass of lead (II) chloride that will be precipitated.
[Pb = 207, Cl= 35.5, N = 14, O = 16]

A. 2.78g
B. 5.56g
C. 8.34g
D. 11.12g