Which gas law relates temperature and volume at constant pressure?

• A. Charles's Law
• B. Boyle's Law
• C. Avogadro's Law
• D. Dalton's Law

Answer: (A)

Charles's Law describes the relationship between temperature and volume of a gas when pressure is held constant. According to this law, when the temperature of a gas increases, its volume also increases, as long as the pressure does not change. This relationship can be mathematically expressed as V/T = k, where V is the volume, T is the absolute temperature, and k is a constant.

This principle is significant in many real-world applications, such as understanding how gas expands when heated. For instance, when air inside a balloon warms up, it expands, resulting in an increase in volume. This concept is crucial in various scientific fields, including meteorology and engineering, when predicting how gases will behave under different temperature conditions.

The other laws mentioned do not specifically relate temperature and volume under constant pressure. Boyle’s Law focuses on the relationship between pressure and volume at a constant temperature, Avogadro’s Law deals with the volume of gas and the amount of substance at constant temperature and pressure, and Dalton’s Law pertains to the partial pressures of gases in a mixture. Therefore, Charles's Law is the correct choice for this relationship.