Question 198Motor Plants - 1st Asst/Chief

The correct answer is C) to ensure the compound additions are adequate for controlling dissolved oxygen. Sulfites are commonly added to boiler feedwater to remove dissolved oxygen and prevent corrosion of the boiler and associated piping. Checking for the presence of sulfite in the feedwater is a way to verify that the chemical treatment program is effectively maintaining low dissolved oxygen levels, which is essential for protecting the boiler system. The other answer choices are incorrect because they do not directly relate to the purpose of testing for sulfite. Option A addresses water hardness, option B is about pH control, and option D is about total dissolved solids control - none of which are the primary reason for testing for sulfite in the feedwater.