Practice Exams ChE - 31

1. The enthalpy content of air at 150ºF and 20% RH is
a. 74.8 Btu/lb d.a.
b. 74 Btu/lb d.a.
c. 78 Btu/lb d.a.
d. 71 Btu/lb d.a.
e. none of these

2. A binary azeotrope contains X% - wt A (MW = 100) and Y% - wt B (MW = 200). Express mol fraction of A in terms of X,
a. (X+150)/2
b. 200X/(X+100)
c. X/150
d. 2X/(X+1)
e. none of these

3. In ____ distillation the vapor generated by boiling the liquid withdrawn from contact with the liquid and condensed as fast as it is formed
a. multi-stages
b. fractional
c. differential
d. flash
e. none of these

4. Two very large walls are at constant temperatures of 600ºF and 900ºF. Assuming that the walls behave like black bodies, how much heat in Btu/hr ft^2 must be removed from the colder wall to maintain a constant temperature?
a. 8,956
b. 34,10
c. 3,734
d. 12,625
e. none of these

5. For a gas diffusing in a stagnant layer of another gas, the concentration decreases ___ along the diffusion path
a. linearly
b. geometrically
c. proportionally
d. logarithmically
e. none of these

6. States that the energy is proportional to the new surface produced
a. Pittinger’s law
b. Kick’s law
c. Bond law
d. Energy law
e. none

7. An act for regulation, protection of trademarks, tradenames and service works
a. RA 1752
b. RA 166
c. RA 318
d. RA 6969
e. none of these

8. Cavitation is the result of:
a. static pressure in a fluid becoming less than fluid vapor pressure
b. rivets under impact load
c. exposure of concrete to salt water
d. heat treatment of a low carbon steel
e. improper welding technique

9. a. Lactobacilli
b. Saccharomyces cenerisiae
c. Penicillum chrysogenum
d. Saccharomyces griseus
e. Acetobacter

is used to bring about fermentation of milk

10. The standard equipment recommended for automatically carrying out sieve test procedures with accuracy and dependability is
a. End-Shak Sieve Shaker
b. Braum Sieve Shaker
c. Ro-tap Shaker
d. Dynamic Sieve Shaker
e. None of these