Test 1 - Fall 2021

Question 1

Fick’s Law is used to

Answer 1

determine the ss flux of a component

Question 2

What is always true for equimolar diffusion with any two components (A & B)?

Answer 2

Ja = -Jb

Question 3

In a binary system, the higher the concentration of the less volatile species in the feed to a flash drum

Answer 3

the higher the liquid flow rate leaving the drum

Question 4

Ki=

Answer 4

yi=xi

Question 5

Relative Volatility of components i and j can be defined as

Answer 5

Ki/Kj

Question 6

Energy balance around a distillation column

Answer 6

Fhf + Qc + Qr = Dhd + Bhb

Question 7

Material balance around a condenser

Answer 7

V = L + D

Question 8

Reflux ratio

Answer 8

L/D

Question 9

If the feed enters the distillation column at its dew point, then the slope of the feed line is

Answer 9

0

Question 10

At total reflux

Answer 10

distillate is 0

Question 11

At minimum reflux, the number of stages is

Answer 11

infinite

Question 12

The slope of the top of the operating line in distillation is

Answer 12

L/V

Question 13

The intercept of the bottom operating line in distillation is

Answer 13

(1-Lbar/Vbar)*Xb

Question 14

Column diameter is most dependent on

Answer 14

vapor velocity

Question 15

To determine tray spacing, use:

Answer 15

Propensity of liquid to foam/entrain; Need for person to access top of trays

Question 16

The phenomena of the flowing liquid towards the wall of tower and dispersed in lateral direction is called as

Answer 16

channeling

Question 17

Overall efficiency is

Answer 17

0.5 to 0.7

Question 18

When sizing a column, switching trays to packing usually results in

Answer 18

decreased height

Question 19

HEPT stands for

Answer 19

height equivalent to theoretical plate