34. The major reason dissolved gases are removed from boiler feedwater is because they may cause __________.

Dissolved gases, primarily oxygen and carbon dioxide, are removed from boiler feedwater to prevent corrosion of boiler metal surfaces. These gases react with the steel, causing pitting and general corrosion, which can weaken boiler components. Deaeration is a standard practice to minimize this corrosion, unlike issues such as false water level readings, vapor lock in feed pumps, or condenser vacuum loss, which have distinct causes.