A pressure of 10.0 mm Hg is measured using a constant-volume gas thermometer at a temperature of 50.0°C. What is the pressure (in mm Hg) at the zero-point temperature?
A) 31.8
B) 11.8
C) 8.45
D) 54.6
E) 68.3

Question

Quizplus · Accepted Answer

The pressure at the zero-point temperature (0°C) can be calculated using the ideal gas law, which implies that the pressure of a gas is directly proportional to its temperature when volume and the amount of gas are constant. The formula to convert the temperature from Celsius to Kelvin is T(K) = T(°C) + 273.15. Therefore, the temperature at 50.0°C is 323.15 K (50 + 273.15), and the zero-point temperature (0°C) is 273.15 K. Using the direct proportionality, $P_1/T_1 = P_2/T_2$, where $P_1 = 10.0$ mm Hg at $T_1 = 323.15$ K, and $P_2$ is the pressure at $T_2 = 273.15$ K. Solving for $P_2$, we get $P_2 = P_1 \times (T_2/T_1) = 10.0 \times (273.15/323.15) = 8.45$ mm Hg.

A Pressure of 10