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71.

The flash process is carried out by

A.	reducing the pressure on the feed stream	B.	cooling the feed at constant pressure
C.	increasing the pressure on the feed steam	D.	none of the above

72.

Flash distillation operation is suitable for separating components which

A.	boil at very close temperature	B.	boil at widely different temperature
C.	form minimum boiling azeotrope	D.	form maximum boiling azeotrope

73.

If there is no condensation of carrier steam in the steam distillation of high-boiling organic materials the steam consumption is minimum at

A.	the highest permissible temperature and pressure	B.	the lowest practicable temperature and pressure
C.	the highest permissible temperature and the lowest practicable pressure	D.	the lowest temperature and the highest practicable pressure

74.

If there is no condensation of carrier steam in the steam distillation of high-boiling organic materials

A.	both temperature and pressure must be fixed	B.	either the temperature or the pressure may be fixed
C.	the temperature is always more than 100?C at 1 atm	D.	the temperature is always equal to 100?C at 1 atm

75.

An ideal plate is defined as one where

A.	the vapour and liquid leaving streams are in equilibrium	B.	the vapour and liquid entering streams are in equilibrium
C.	the vapour leaving stream is in equilibrium with the liquid entering stream	D.	the vapour entering stream is in equilibrium with the liquid leaving stream

76.

The intercept on y-axis of the operating line for the rectifying section of a distillation column is where L and V are the liquid and vapour rates in the rectifying section taken to be constant over the section

A.	xD Ri/Ro	B.	xD L/V
C.	D xB/L	D.	none of the above

77.

The slope of the opeating line for the stripping section of distillation column is

A.	0	B.	?
C.	< 1	D.	> 1

78.

If q is interpreted to be the fraction of the feed that is liquid then the slope of the feed line in distillation operation is

A.	?(1-q)/q	B.	?q/(1-q)
C.	?q	D.	?q/(q-1)

79.

When a dephlegmator is also used to condense partially the overhead vapour from a distillation column the liquid reflux at its bubble-point

A.	has the same composition as the overhead product	B.	is richer in less volatile component than overhead product
C.	is richer in more volatile component than overhead product

80.

If q is interpreted to be the fraction of the feed stream that is liquid then for saturated vapour feed to a distillation column

A.	q = 1	B.	q = 0
C.	q > 1	D.	q < 0