CPO Chemical Handling and Storage 4

Question 1

Superchlorination (breakpoint chlorination) requires free chlorine to reach what target level?

Accepted Answer

10 times the combined chlorine (chloramine) level in the water

Answer

Breakpoint chlorination requires free chlorine equal to 10 times the combined chlorine level to fully oxidize chloramines and restore water quality.

Question 2

Calcium hypochlorite granules should NEVER be pre-dissolved in a container that previously held:

Accepted Answer

Another pool chemical such as trichlor or acid

Answer

Residue from prior chemicals—especially other chlorine types or acid—can react violently with cal hypo, causing ignition, fire, or explosion.

Question 3

Chlorine gas cylinders must be stored in which position?

Accepted Answer

Upright and secured with a restraint chain or strap

Answer

Gas cylinders must be kept upright and restrained because a falling cylinder can shear the valve, causing a catastrophic, uncontrolled gas release.

Question 4

If chlorine gas is detected leaking in an equipment room, the operator's FIRST action should be to:

Accepted Answer

Evacuate everyone from the area and call emergency services

Answer

Chlorine gas is immediately dangerous to life and health (IDLH) at 10 ppm; immediate evacuation and calling 911 is the only safe response without SCBA equipment.

Question 5

Approximately how much 10% sodium hypochlorite (liquid chlorine) is needed to raise free chlorine by 1 ppm in a 100,000-gallon pool?

Accepted Answer

1 gallon

Answer

The standard rule of thumb is approximately 1 gallon of 10% sodium hypochlorite per 100,000 gallons of water to raise free chlorine by 1 ppm.

CPO (Certified Pool Operator Exam) Practice Test

CPO (Certified Pool Operator Exam) Practice Test

CPO Chemical Handling and Storage 4