Practice Pakistan's most useful MCQs for competitive exams

Pure aniline is evaporating through a stagnant air film of 1 mm thickness at 300 K and a total pressure of 100 KPa. The vapor pressure of aniline at 300 K is 0.1 KPa. The total molar concentration under these conditions is 40.1 mole/m3. The diffusivity of aniline in air is 0.74 × 10-5m2/s. The numerical value of mass transfer co-efficient is 7.4 × 10-3. Its units are_______________________?

• (A)  m/s
• (B)  cm/s
• (C)  mole/m2.s.Pa
• (D)  k.mole/m2.s.Pa

Answer

Submitted By :Ali Uppal

The reverse process of fractional crystallisation is called__________________?

• (A)  Stripping
• (B)  Leaching
• (C)  Differential distillation
• (D)  Absorption

Answer

Submitted By :Ali Uppal

Which of the following is the Clausius-Clapeyron Equation ?

• (A)  PV = RT + B/V + y/V2 + ….
• (B)  (P + a/V2)(V-b) = RT
• (C)  loge (p/p0) = (λ/R) (1/T0 – 1/T)
• (D)  p = [RT/(V – b)] – (a/TV2)

Answer

Submitted By :Ali Uppal

Weight of 56 litres of ammonia at N.T.P. is _____________ gm?

• (A)  2.5
• (B)  42.5
• (C)  56
• (D)  2800

Answer

Submitted By :Ali Uppal

Molality is defined as the number of gm moles of solute per _____________ of solvent?

• (A)  Litre
• (B)  kg
• (C)  gm.mole
• (D)  gm

Answer

Submitted By :Ali Uppal

A solution with reasonably permanent pH is called a/an _______________ solution?

• (A)  Ideal
• (B)  Non-ideal
• (C)  Buffer
• (D)  Colloidal

Answer

Submitted By :Ali Uppal

The heat capacity of a solid compound is calculated from the atomic heat capacities of its constituent elements with the help of the___________________?

• (A)  Trouton’s rule
• (B)  Kopp’s rule
• (C)  Antoine equation
• (D)  Kistyakowsky equation

Answer

Submitted By :Ali Uppal

The molecular velocity of a real gas is proportional to (where, T = absolute temperature of the gas)?

• (A)  √T
• (B)  T
• (C)  T2
• (D)  1/√T

Answer

Submitted By :Ali Uppal

Solutions having the same osmotic pressure are called _____________ solutions?

• (A)  Dilute
• (B)  Ideal
• (C)  Isotonic
• (D)  Saturated

Answer

Submitted By :Ali Uppal

Which of the following ideal gas laws are not applicable to mixture of gases ?

• (A)  Amagat’s law
• (B)  Dalton’s law
• (C)  Boyle’s law & Charle’s Law
• (D)  None of these

Answer

Submitted By :Ali Uppal