Practice Pakistan's most useful MCQs for competitive exams

A solution is made by dissolving 1 kilo mole of solute in 2000 kg of solvent. The molality of the solution is_________________?

• (A)  2
• (B)  1
• (C)  0.5
• (D)  0.05

Answer

Submitted By :Ali Uppal

Avogadro number is the number of molecules in one ____________ of a gas?

• (A)  gram
• (B)  Kilogram
• (C)  gm.mole
• (D)  Litre

Answer

Submitted By :Ali Uppal

The pressure of ‘V’ litres of a dry gas is increased from 1 to 2 kgf/cm2 at a constant temperature. The new volume will become___________________?

• (A)  V/2
• (B)  2V
• (C)  V/4
• (D)  V2

Answer

Submitted By :Ali Uppal

For a given mass of a gas at constant temperature, if the volume ‘V’ becomes three times, then the pressure ‘P’ will become______________?

• (A)  P/3
• (B)  3P
• (C)  9P2
• (D)  9P

Answer

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One Newton is equal to ______________ dynes?

• (A)  102
• (B)  103
• (C)  104
• (D)  105

Answer

Submitted By :Ali Uppal

In a binary liquid solution of components „A‟ and „B‟, if component „A‟ exhibits positive deviation from Raoult’s law, then component „B‟ ?

• (A)  Exhibits positive deviation from Raoult’s law
• (B)  Exhibits negative deviation from Raoult’s law
• (C)  Obeys Raoult’s law
• (D)  May exhibit either positive or negative deviation from Raoult’s law

Answer

Submitted By :Ali Uppal

_____________ kg of CaC03 on heating will give 56 kg of CaO?

• (A)  56
• (B)  100
• (C)  144
• (D)  1000

Answer

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The elevation in boiling point of a solution is proportional to the ______________ of the solution?

• (A)  Molal concentration
• (B)  Reciprocal of the molal concentration
• (C)  Normality
• (D)  Molarity

Answer

Submitted By :Ali Uppal

What is the total pressure exerted by a mixture of 0.45 kg mole of benzene, 0.44 kg mole of toluene and 0.23 kg mole of o-xylene at 100°C, if their vapor pressures at 100°C are 1340, 560 and 210 mmHg respectively ?

• (A)  756.2
• (B)  780.5
• (C)  801.5
• (D)  880.5

Answer

Submitted By :Ali Uppal

The evaporation of aqueous solution of sugar causes its molarity to__________________?

• (A)  Decrease
• (B)  Increase
• (C)  Remain unchanged
• (D)  Either

Answer

Submitted By :Ali Uppal