Question 1
A soil vapor extraction system equipped with carbon canisters is used to remediate gasoline contamination at a gas station. Which of the following statement is TRUE?
Activated carbon in the canisters filters the gasoline vapors by the process of absorption.
Activated carbon is charcoal heated in the absence of air at low temperatures.
Activated carbon is an effective filter medium for gasoline vapors because of its small surface area.
Activated carbon in the canisters filters gasoline vapors by the process of adsorption.

Question 2
Diamond and graphite are the two primary allotropes of carbon. Neither is generally considered hazardous, but they have their own specific uses. Choose which of the following statements is TRUE regarding these allotropes.
Diamond and graphite undergo phase changes from solid to liquid at moderately high temperature.
Diamond and graphite do not burn.
Diamond and graphite have different chemical structures.
Diamond and graphite are poor conductors of heat.

Question 3
A contractor was hired to do some maintenance work inside a grain silo. Assuming the facility is at sea level, what is the minimum level of oxygen necessary for the contractor to carry out his or her task without using a supplied air respirator?
16.0%
19.5%
20.9%
23.5%

Question 4
Which of the following statements regarding oxygen is FALSE?
There are three allotropes of oxygen: GOX, LOX, and ozone.
LOX is cryogenic oxygen.
Gaseous oxygen under increased pressure is called hyperbaric oxygen.
Industrial facilities that use large quantities of oxygen often store it as the cryogenic liquid.

Question 5
Underground coal mining presents workers with many hazards EXCEPT which of the following? Choose the best answer.
Potential for fire and explosion due to methane
Prolonged inhalation of coal dust could cause pneumonoconiosis (black lung disease)
Mine collapse
Skin irritation

Question 6
Although coal is no longer the favored energy source, U.S. coal mines still produced close to a billion short tons of coal. Match the description of the following chemical products obtained from or related to coal.

Coke
Carbon black
Coal gas
Coal tar pitch
Coal tar
Creosote oil
Coal tar distillate
Anthracite
Lignite
Charcoal

A. Coal that has 0.4 to 1.9% sulfur content
B. Coal that has a specific gravity of 1.29
C. Solid residue that is left when coal and coal tar pitch are heated in the absence of air
D. Any fraction obtained by distilling coal tar
E. Residue left after coal is heated to 350 deg C in the absence of air
F. A finely divided form of carbon that is produced when coal tar burns in a furnace with limited air
G. Product obtained from the distillation of coal tar
H. Residue remaining after wood, nut shells or peach pits are heated in the absence of air
I. Mixture consisting of ammonia, carbon monoxide, hydrogen cyanide, methane, and hydrogen sulfide produced when coal is heated in the absence of air
J. Liquid produced from the heating of coal that can be used for waterproofing when sealing roofs