Practice Pakistan's most useful MCQs for competitive exams

Pure oxygen is mixed with air to produce an enriched air containing 50 volume % of oxygen. The ratio of moles of air to oxygen used is_________________?

• (A)  1.72
• (B)  0.58
• (C)  0.5
• (D)  0.2

Answer

Submitted By :Ali Uppal

Elements in a periodic table are arranged in order of their__________________?

• (A)  Atomic number
• (B)  Mass number
• (C)  Atomic weight
• (D)  Metallic characteristics

Answer

Submitted By :Ali Uppal

The most convenient way of expressing solution concentration is in terms of___________________?

• (A)  Mole fraction
• (B)  Normality
• (C)  Molality
• (D)  Molarity

Answer

Submitted By :Ali Uppal

Disappearance of snow in subzero weather exemplifies the process of_________________?

• (A)  Evaporation
• (B)  Sublimation
• (C)  Vaporisation
• (D)  Melting

Answer

Submitted By :Ali Uppal

The vapour pressure of water is given by, in Psat = A – (5000/T), where A is a constant, Psat is the vapour pressure in atm. and T is the temperature in K. The vapor pressure of water in atm. at 50°C is approximately__________________?

• (A)  0.07
• (B)  0.09
• (C)  0.11
• (D)  0.13

Answer

Submitted By :Ali Uppal

In a mixture of benzene vapor and nitrogen gas at a total pressure of 900 mm Hg, if the absolute humidity of benzene is 0.2 kg benzene/kg nitrogen, the partial pressure of benzene in mm Hg is__________________?

• (A)  180
• (B)  60.3
• (C)  720
• (D)  200

Answer

Submitted By :Ali Uppal

Volume occupied by one gm mole of a gas at S.T.P. is ____________________?

• (A)  22.4 litres
• (B)  22400 litres
• (C)  22.4 c.c
• (D)  359 litres

Answer

Submitted By :Ali Uppal

Which of the following has the least (almost negligible) effect on the solubility of a solute in a solvent ?

• (A)  Temperature
• (B)  Nature of solute
• (C)  Pressure
• (D)  Nature of solvent

Answer

Submitted By :Ali Uppal

According to the kinetic theory, the thermal conductivity of a monatomic gas is proportional to___________________?

• (A)  T
• (B)  T0.5
• (C)  T1.5
• (D)  T2

Answer

Submitted By :Ali Uppal

Sodium ______________ has inverted solubility curve i.e. its solubility increases with the lowering of temperature?

• (A)  Carbonate (monohydrate)
• (B)  Chloride
• (C)  Thiosulphate
• (D)  Bisulphite

Answer

Submitted By :Ali Uppal