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This set of Mass Transfer Multiple Choice Questions & Answers (MCQs) focuses on Mass Transfer Set 22
Q1 | In a binary system, separation is very efficient, when the relative volatility is
- 1
- > 1
- < 1
- 0.5
Q2 | The following plot gives the saturated humidity (He) versus temperature (T).Line joining (H1, T1) and (H2, T2) is the constant enthalpy line. Choose the correct one from among the alternatives A, B, C and D.
- T1-Dew point temp; T2-Dry bulb temp; T3-Wet bulb temp
- T1-Dew point temp; T2-Wet bulb temp; T3-Dry bulb temp
- T1-Wet bulb temp; T2-Dry bulb temp; T3-Dew point temp
- T1-Dry bulb temp; T2-Wet bulb temp; T3-Dew point temp
Q3 | Channelling in a packed tower results from the
- High pressure drop
- Maldistribution of liquid
- Non-uniformity of packing
- Both (B) and (C)
Q4 | Which of the following adsorbent is used in the refining of sugar?
- Bone charcoal
- Wood charcoal
- Silica gel
- Activated clay
Q5 | With increase in pressure, the relative volatility for a binary system
- Increases
- Decreases
- Remains same
- Either (A) or (B), depends on the system
Q6 | When the liquid over a plate is of uniform concentration, then
- Murphree efficiency > point efficiency
- Murphree efficiency < point efficiency
- Murphree efficiency = point efficiency
- Murphree efficiency ? point efficiency
Q7 | Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids, when
- Extracting solvent is cheaply & abundantly available
- One of the liquid components is heat sensitive
- Viscosity of liquid components is very high
- One of the liquid components has very high affinity towards the solvent
Q8 | A good solvent used for absorption should not have very high
- Viscosity
- Vapor pressure
- Freezing point
- All (A), (B) & (C)
Q9 | An example of elution is
- Separation of uranium oxide from its ore by H2SO4 in a Pachuca tank
- Separation of sugar from sugar beet by hot water
- Dissolution of tannin out of tree barks by water
- Recovery of vegetable oils from seeds
Q10 | The term "cooling range" in a cooling tower refers to the difference in the temperature of
- Cold water leaving the tower and the wet bulb temperature of the surrounding air
- Hot water entering the tower and the wet bulb temperature of the surrounding air
- Hot water entering the tower and the cooled water leaving the tower
- None of these
Q11 | If the amount of the steam used in steam distillation is increased, the temperature of distillation
- Increases
- Decreases
- Remains unchanged
- Depends on relative volatility
Q12 | Rate of leaching increases with increasing
- Temperature
- Viscosity of solvent
- Pressure
- Size of the solid
Q13 | With increase in gas rate, the number of transfer units, NtoG, for a fixed degree of absorption by a fixed amount of solvent
- Increases
- Decreases
- Decreases linearly
- Remains unaffected
Q14 | Heat load in a cooling tower
- Means the amount of heat thrown away (KCal/hr.) by the cooling tower
- Is equal to the number of kg, of water circulated times the cooling range
- Both (A) & (B)
- Neither (A) nor (B)
Q15 | Separation of two or more components of a liquid solution cannot be achieved by
- Fractional crystallisation
- Liquid extraction
- Absorption
- Evaporation
Q16 | For __________ drying, the effects of velocity, temperature and humidity of the gas and thethickness of the solid are the same.
- Unsaturated surface
- Constant rate
- Both (A) and (B)
- Neither (A) nor (B)
Q17 | In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as
- Ri = Re/(1 - Re)
- Ri = (1 - Re)/Re
- Ri = Re
- Ri = Re/(1 + Re)
Q18 | Deaeration (removal of O2) of water is done by
- Rectification
- Absorption
- Ion-exchange
- Adsorption
Q19 | For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because
- Water has a high latent heat of evaporation
- Lewis number is close to unity
- They are always equal under all circumstances
- Solubility of the components of air in water is very small
Q20 | Dew point of a gas-vapour mixture
- Increases with temperature rise
- Decreases with temperature rise
- Decreases with decrease in pressure
- Increases with increase in pressure
Q21 | If moisture content of solid on dry basis is X, then the same on wet basis is
- X/(X + 1)
- X/(1 - X)
- (1 + X)/X
- (1 - X)/X
Q22 | __________ temperature is the steady state temperature attained by a small amount of liquid evaporating into a large quantity of unsaturated gas-vapor mixture.
- Dry bulb
- Wet bulb
- Dew point
- None of these
Q23 | The-relative volatility for separation of a non-ideal binary mixture by distillation should be
- 0
- 1
- > 1
- < 1
Q24 | In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapour, because
- Temperature is less
- Total pressure is less
- Mixing of steam with the material being vaporised is not so intimate as to result in equilibrium condition
- Saturated steam is used for steam distillation
Q25 | Which of the following unit operations makes use of Thiele-Geddes equation?
- Liquid-liquid extraction
- Solid-liquid extraction
- Multi-component absorption with chemical reaction
- Multi-component distillation