Given a fixed amount of gas held at constant pressure, calculate the temperature to which the gas would have to be changed if a 3.50 L sample at 23.0°C were to have a final volume of 1.50 L.
A)2.0°C
B)127°C
C)−146°C
D)9.8°C
E)43.2°C

Question

Quizplus · Accepted Answer

We can use the combined gas law to solve for the final temperature:

(P1V1)/T1 = (P2V2)/T2

We know P1 = P2 (constant pressure), V1 = 3.50 L, V2 = 1.50 L, and T1 = 23.0°C + 273.15 K = 296.15 K.

Plugging in the values and solving for T2:

(1 atm)(3.50 L)/(296.15 K) = (1 atm)(1.50 L)/T2
T2 = 125.10 K = -146°C (rounded to 3 significant figures)

Therefore, the answer is C, -146°C.

Given a Fixed Amount of Gas Held at Constant Pressure