Which of the following are factors that accelerate general corrosion?

• A. Increase in temperature
• B. Increase in dissolved oxygen
• C. Decrease in pH
• D. All of the above

Answer: (D)

General corrosion is driven by electrochemical reactions at the metal surface, so factors that speed those reactions or increase the supply of reactants tend to boost the corrosion rate.

Raising temperature speeds chemical kinetics and diffusion of ions in the boundary layer, so both the metal dissolution (anodic) and the reduction (cathodic) steps proceed faster. More dissolved oxygen means more oxidant is available for the cathodic reaction, increasing the overall current and accelerating uniform metal loss. Lower pH means a more acidic environment with higher H+ concentration, which promotes easier dissolution of the metal and can destabilize protective surface films, reducing passivity and increasing the rate of attack.

Because each of these factors—temperature, dissolved oxygen, and acidity (lower pH)—pushes the corrosion process in the same direction, they all contribute to faster general corrosion.