Practice Exams ChE - 29

1. If CA is plotted versus time and a straight line is observed, the reactions is said to be
a. 1st order
b. 2nd order
c. zero
d. fractional order
e. none of these

2. The order of magnitude of diffusivities of gases is
a. 10^-5 m^2/s
b. 10^-3 m^2/s
c. 10^-9 m^2/s
d. 10^-14 m^2/s
f. none of these

3. Heat-loving organisms that exist at minimum temperature range of 25-45ºC to optimum temperature range of 50-55ºC and maximum temperature range of 60-85ºC
a. psycrophiles
b. mesophiles
c. thermophiles
d. chromagenes
e. none of these

4. The pressure drop of the fluid flowing through a conduit is
a. zero as the velocity is constant
b. not affected by flow regime
c. not affected by conduit material
d. much higher during turbulent flow
e. none of these

5. a. papase
b. pepsin
c. bromelin
d. lipase
e. hydrase

is derived from papaya as natural meat tenderizer.

6. The source that gives the highest percentage of CO and NOx emission to the atmosphere is:
a. transportation facilities
b. stationary sources
c. industrial plants excluding stationary sources therein
d. natural sources such as fires and volcanic eruptions
e. crushing of cemented roads

7. The US standard sieve series equivalent to 24 mesh Tyler standard is ___ microns
a. 606
b. 400
c. 805
d. 707
e. none of these

8. A slurry of flaked soybeans weighing 100 kg contains 75 kg inert solids and 25 kg solution with 10% oil and 90% weight solvent hexane. This slurry is contacted with 100 kg pure hexane in a single stage so that the value of retention for the outlet underflow is 1.5 kg of insoluble solid per kg solvent in the adhering solution. What is the composition of underflow leaving the extraction stage in percent by weight oil?
a. 1.5
b. 2.3
c. 0.3
d. 0.8
e. none of these

9. The amount of radiation emitted in all directions and overall wavelengths by a perfect emitter is proportional to the fourth power of the absolute temperature of the emitter. This is the statement of:
a. Stefan-Boltzman law
b. Kirchoff’s law
c. Wein’s law
d. Planck’s law
e. None of these

10. In the removal of a solute from a water phase by liquid extraction using a membrane, it is advantageous to use
a. polymer membrane
b. any porous membrane
c. hydrophobic membrane
d. asymmetric membrane
e. none of these