A sample of gas initially occupies 5.50 L at a pressure of 0.750 atm at 13.0°C. What will the pressure be if the temperature is changed to 22.5°C, and the volume is changed to 1.50 L?

Question

Quizplus · Accepted Answer

First, we need to use the ideal gas law to find the initial number of moles of the gas: 
PV = nRT 
n = PV/RT = (0.750 atm)(5.50 L)/(0.0821 L·atm/mol·K)(13.0°C + 273) = 0.141 mol

Next, we can use the combined gas law to find the new pressure: 
P1V1/T1 = P2V2/T2 
(0.750 atm)(5.50 L)/(13.0°C + 273) = P2(1.50 L)/(22.5°C + 273) 
P2 = (0.750 atm)(5.50 L)(22.5°C + 273)/(13.0°C + 273)(1.50 L) = 2.84 atm

Therefore, the answer is choice D, 2.84 atm.

A Sample of Gas Initially Occupies 5