🔍 Key Concepts

• Boiler water hardness and what causes it (calcium and magnesium salts) • Common effects of hardness inside boilers (think about what forms on metal heating surfaces) • Difference between carryover/foaming problems and solid deposits on waterside surfaces

💭 Think About

• Ask yourself: When feedwater is described as "hard," what is actually dissolved in it, and what happens to those substances when the water is heated to boiling? • Which of these answer choices describes something that physically builds up on the internal metal surfaces of the boiler rather than a behavior of the steam or water? • Think about which problem is most directly connected to calcium/magnesium precipitating out and sticking to the boiler metal.

✅ Before You Answer

• Identify which choice refers to a solid deposit on boiler waterside surfaces rather than a condition of the steam or liquid interface. • Confirm which problems (foaming, carryover, alkalinity) are often results of poor water chemistry in general, versus the specific, typical result of hardness. • Make sure you can explain in your own words how calcium and magnesium in water lead to the condition described in your chosen answer.