A. Temperature is less
B. Total pressure is less
C. Mixing of steam with the material being vaporised is not so intimate as to result in equilibrium
condition
D. Saturated steam is used for steam distillation
Related Mcqs:
- The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by __________________?
A. Raising the temperature
B. Lowering the total pressure
C. Both A. and B.
D. Neither A. nor B. - The feed to fractionating column is changed from saturated vapour to saturated liquid. If the separation and reflux ratio remains unchanged, the number of ideal stages will______________________?
A. Increase
B. Decrease
C. Remain same
D. Depend on saturated boiling point; may increase or decrease - Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid) ?
A. p = P
B. p >>P
C. p < P
D. p << P - If the solubilities of different components (in a liquid-liquid extraction system) increase with rise in temperature, then the temperature above which they dissolve completely is known as the critical solution temperature (CST or consolute temperature). If solubilities increase with decrease in temperature, then CST is the temperature below which they dissolve completely. If a binary system has no critical solution temperature, it implies that___________________?
A. The system comprises of partially miscible liquids
B. The system comprises of miscible liquids
C. The system comprises of an azeotrope
D. On heating, a vapor phase will appear; while on cooling, a solid phase will appear - In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed____________________?
A. q > 1
B. q < 1
C. q = 1
D. q = 0 - An air-water vapour mixture has a dry bulb temperature of 60°C and a dew point temperature of 40°C. The total pressure is 101.3 kPa and the vapour pressure of water at 40°C and 60°C are 7.30 kPa and 19.91 kPa respectively. The humidity of air sample expressed as kg of water vapour/kg of dry air is__________________?
A. 0.048
B. 0.079
C. 0.122
D. 0.152 - On moving the feed line (q-line) from saturated liquid feed (vertical position) to saturated vapor feed (horizontal feed), if the slope of both the operating lines are to be increased, then it will result in______________________?
A. Greater degree of separation with a fixed number of trays
B. Increased reboiler load
C. Increased reflux ratio
D. None of these - In the layout plan for a vacuum distillation unit, operating at 60 mm Hg, supported by a barometric condenser, the appropriate place for the location of vacuum drum for collecting the distillate will be___________________?
A. At ground level
B. 2 metres above the ground
C. 5 metres above ground
D. 10 metres above ground - In the layout plan for a vacuum distillation unit, operating at 60 mm Hg, supported by a barometric condenser, the appropriate place for the location of vacuum drum for collecting the distillate will be_____________________?
A. At ground level
B. 2 metres above the ground
C. 5 metres above ground
D. 10 metres above ground - A distillation column separates 10000 kg/hr of a benzene-toluene mixture as shown in the figure below: In the figure xF, xD and xW represent the weight fraction of benzene in the feed, distillate and residue respectively. The reflux ratio is_______________ ?
A. 0.5
B. 0.6
C. 1.0
D. 2.0
