A fully charged lead-acid battery will not freeze until extremely low temperatures because

A fully charged lead-acid battery will not freeze until extremely low temperatures because

• A. most of the acid is in the solution
• B. the plates prevent freezing
• C. the electrolyte is pure water
• D. the electrolyte temperature remains constant due to ambient heating

Answer: (A)

The main idea is freezing point depression: dissolved substances lower the temperature at which a liquid freezes. In a fully charged lead‑acid battery, the electrolyte is a concentrated sulfuric acid solution, so most of the acid is in the liquid phase. The sulfuric acid ions disrupt ice formation, driving the freezing point of the electrolyte well below that of pure water. Because the electrolyte remains liquid at temperatures where water would freeze, the battery won’t freeze until temperatures are extremely low. The plates don’t prevent freezing, and the electrolyte isn’t pure water, and ambient heating isn’t the mechanism here.

The main idea is freezing point depression: dissolved substances lower the temperature at which a liquid freezes. In a fully charged lead‑acid battery, the electrolyte is a concentrated sulfuric acid solution, so most of the acid is in the liquid phase. The sulfuric acid ions disrupt ice formation, driving the freezing point of the electrolyte well below that of pure water. Because the electrolyte remains liquid at temperatures where water would freeze, the battery won’t freeze until temperatures are extremely low. The plates don’t prevent freezing, and the electrolyte isn’t pure water, and ambient heating isn’t the mechanism here.