The formation of a pit in the surface of a...

Question 1 / 270705eccefa0bacbc34ba4d46cb7

Question 1 of 270705eccefa0bacbc34ba4d46cb7

The formation of a pit in the surface of a boiler tube is most likely to occur when __________.

Question 1 of 27070

The formation of a pit in the surface of a boiler tube is most likely to occur when __________.

🔍 Key Concepts

• pitting corrosion on boiler tubes • difference between general corrosion and localized attack • role of anodes and cathodes in electrochemical corrosion cells

💭 Think About

• Which condition creates a tiny, highly concentrated corrosion cell at a specific spot on the metal surface, instead of evenly over a wide area? • Think about how an anode behaves in a corrosion cell: does the metal at the anode get protected or attacked? • Which choice describes the electrochemical role of the tube metal itself, rather than just what’s in the water?

✅ Before You Answer

• Identify which option focuses on the electrical role of the tube metal (anode vs. cathode), not just contaminants. • Ask yourself: pitting is localized metal loss. Which option directly implies metal being sacrificed/dissolved at a point? • Eliminate answers that only describe common boiler water impurities without explaining a corrosion mechanism that creates pits.

Question 1 of 27070

The formation of a pit in the surface of a boiler tube is most likely to occur when __________.

waterside deposits are present

sludge is present

the tube metal acts as an anode

dissolved minerals are present