Practice Pakistan's most useful MCQs for competitive exams

Osmotic pressure exerted by a solution prepared by dissolving one gram mole of a solute in 22.4 litres of a solvent at 0°C will be _______________ atmosphere?

• (A)  0.5
• (B)  1
• (C)  1.5
• (D)  2

Answer

Submitted By :Ali Uppal

A car tyre of volume 0.057 m3 is inflated to 300 kPa at 300 K. After the car is driven for 10 hours, the pressure in the tyre increases to 330 kPa. Assume air is an ideal gas and Cv for air is 21 J/mole.K. The change in the internal energy of air in the tyre in J/mole is__________________?

• (A)  380
• (B)  630
• (C)  760
• (D)  880

Answer

Submitted By :Ali Uppal

500 c.c. each of hydrogen at 700 mm Hg pressure and oxygen at 600 mm Hg pressure are put together in a vessel of 1 litre capacity. The final pressure of the gas mixture will be _____________ mm Hg?

• (A)  650
• (B)  700
• (C)  600
• (D)  375

Answer

Submitted By :Ali Uppal

A gas at 0°C was subjected to constant pressure cooling until its volume became half the original volume. The temperature of the gas at this stage will be________________?

• (A)  0°C
• (B)  0°K
• (C)  -136.5°C
• (D)  -136.5°K

Answer

Submitted By :Ali Uppal

A fluid gas produced on burning furnace oil contains 0.15 gm mole of CO2, 0.05 gm mole of oxygen and 0.80 gm mole of N2. What is its molecular weight ?

• (A)  28.6
• (B)  30.0
• (C)  30.6
• (D)  32.6

Answer

Submitted By :Ali Uppal

1 Kcal/kg. °C is equivalent to _______________ BTU/lb. °F ?

• (A)  1
• (B)  2.42
• (C)  4.97
• (D)  None of these

Answer

Submitted By :Ali Uppal

For the gaseous phase reaction, N2 + O2 ⇌ 2NO, ΔH = + 80 kJ/kg. mole; the decomposition of NO is favoured by____________________?

• (A)  Increasing the concentration of N2
• (B)  Decrease in temperature
• (C)  Increase in pressure
• (D)  Decrease in pressure

Answer

Submitted By :Ali Uppal

In _______________ process, ions of salts react with water to produce acidity or alkalinity ?

• (A)  Hydration
• (B)  Hydrolysis
• (C)  Electrolysis
• (D)  Dialysis

Answer

Submitted By :Ali Uppal

The value of (Cp – Cv) for a real gas obeying Vander Wall’s equation is____________________?

• (A)  R
• (B)  > R
• (C)  < R
• (D)  0.5 R

Answer

Submitted By :Ali Uppal

One ‘Therm’ is equivalent to___________________?

• (A)  105 BTU
• (B)  105 kcal
• (C)  109 BTU
• (D)  109 kcal

Answer

Submitted By :Ali Uppal