unit 28 review

In order to keep dry ice in the solid form, the temperature of its surroundings can be ____.

• 30°F

• -41°F

• -100°F

• -125°F

Nitrogen changes from a liquid to a vapor at ____.

• 212°F

• -21°F

• -320°F

• -479°F

Cold plates are usually filled with a ____.

• brine solution

• eutectic solution

• sodium chloride or calcium chloride solution

• All of the above.

Dry ice is composed of ____.

• liquid nitrogen

• liquid carbon dioxide

• solidified carbon dioxide

• solidified ammonia

A eutectic solution is a(n) ____.

• phase change solution

• very warm solution

• acid solution

• explosive solution

In some applications of truck refrigeration, a liquid refrigerant is sprayed directly into the truck box to maintain low temperatures. The liquid refrigerant used is ____.

• oxygen

• nitrogen

• R22

• ammonia

Truck refrigeration systems are designed to have the capacity to ____.

• refrigerate a load that is not down to temperature

• refreeze a load that has thawed

• hold the load temperature when in transit

• All of the above.

Where are cascade systems primarily used?

• Extra-low temperature range.

• Low temperature range.

• Medium and low temperature ranges.

Ammonia is extremely toxic to humans and must be used with care. When working with ammonia systems it is often necessary for the technician to wear ____.

• goggles

• breathing apparatus

• protective clothing

• All of the above.

Seawater-cooled condensers for marine use have ____.

• removable water box covers

• water circulating in the tubes

• tubes that are accessible for cleaning using a brush

• All of the above.