Chelation controls _______, and sequestration controls _______.

Chelation controls _______, and sequestration controls _______.

• A. Scale, corrosion
• B. Corrosion, scale
• C. Scale, scale
• D. Corrosion, corrosion

Answer: (C)

Chelation and sequestration are chemical methods used to keep dissolved metal ions from precipitating and forming solid deposits. Chelation binds calcium and magnesium ions tightly, preventing them from reacting to form scale on pipes and heat exchangers. Sequestration does a similar job by using agents (often phosphates or polyphosphates) to keep those hardness ions in solution, which also helps prevent scale buildup. That’s why both parts point to scale as what they control. Corrosion, on the other hand, is typically addressed through pH/alkalinity control and corrosion inhibitors, not primarily by chelating or sequestrating ions, which is why the other considerations don’t fit as well.

Chelation and sequestration are chemical methods used to keep dissolved metal ions from precipitating and forming solid deposits. Chelation binds calcium and magnesium ions tightly, preventing them from reacting to form scale on pipes and heat exchangers. Sequestration does a similar job by using agents (often phosphates or polyphosphates) to keep those hardness ions in solution, which also helps prevent scale buildup.

That’s why both parts point to scale as what they control. Corrosion, on the other hand, is typically addressed through pH/alkalinity control and corrosion inhibitors, not primarily by chelating or sequestrating ions, which is why the other considerations don’t fit as well.