Question

why is it necessary to use the gay - lussac law ($\frac{p_1}{t_1}=\frac{p_2}{t_2}$) to calculate the pressure of the air at higher temperatures? select one: because the amount of air in the flask changes as it is heated. because any air that leaks out of the stopper corrects this calculation. this law is used to calculate the vapor pressure directly. because the pressure of a fixed amount of gas in a sealed container increases as its temperature increases.

Explanation:

Step1: Recall Gay - Lussac's Law conditions

Gay - Lussac's Law ($\frac{P_1}{T_1}=\frac{P_2}{T_2}$) applies to a fixed amount of gas in a sealed container. It states that the pressure of a gas is directly proportional to its temperature when the volume and amount of gas are constant.

Step2: Analyze the options

If the amount of air in the flask changes as it is heated (for example, if air leaks out of the stopper), the amount of gas is no longer fixed. Gay - Lussac's Law requires a fixed amount of gas for the pressure - temperature relationship to hold. So, if the amount of air changes, the law cannot be used to calculate the vapor pressure directly.

Answer:

Because the amount of air in the flask changes as it is heated.