$4.$ Which of the following is a common ion exchanger used in demineralization processes?

a$)$ Calcium sulfate

b$)$ Sodium carbonate

c$)$ Zeolite

d$)$ Activated carbon

What is the purpose of regenerating ion exchange resins in demineralization processes?

a$)$ To remove suspended solids

b$)$ To restore their ion exchange capacity

c$)$ To reduce pH

d$)$ To enhance taste and odor

What is the primary function of a deaerator in a boiler feed water system?

a$)$ To remove dissolved gases

b$)$ To increase the temperature of water

c$)$ To add minerals to water

d$)$ To regulate the pressure inside the boiler

Which of the following is a common method for reducing dissolved oxygen in boiler feed water?

a$)$ Adding oxygen scavengers

b$)$ Increasing the temperature

c$)$ Decreasing the pressure

d$)$ Adding disinfectants