A tightly sealed 4.0-L flask contains 884 mm Hg of N₂ at 94.0°C.The flask is cooled until the pressure is reduced to 442 mm Hg.What is the temperature of the gas?

Question

Quizplus · Accepted Answer

We can use the combined gas law, which states PV/T = constant, to solve for the final temperature. Initially, the pressure is 884 mm Hg and temperature is 94.0°C, so the initial value of PV/T is (884 mm Hg)(4.0 L)/(367.15 K). When the pressure is reduced to 442 mm Hg, we can solve for the new temperature: (442 mm Hg)(4.0 L)/(PV) = T. Plugging in the initial value of PV/T, we get T = (442 mm Hg)(4.0 L)/(884 mm Hg)(4.0 L)/(367.15 K) = 284.65 K = -88.5°C. Note that we have to convert mm Hg to atm for the combined gas law, but the units cancel out in the calculation. We choose the answer that is closest to this value, which is choice C.

A Tightly Sealed 4