A sample of hydrogen at 27ºC exerts a pressure of 700 mm Hg. The gas is heated to 57ºC at constant volume, what will its new pressure be {in psi}?

Question

Process and answer is needed!

Answer 1

This is a P1V1 = P2T2 type of problem

T1 T2

P1, V1 and T1 are the initial pressure, volume, and temperature.

P2, V2 and T2 are the final pressure, volume, and temperature.

V1 = V2 since the question states it is "constant volume"

T1 and T2 need to be in absolute temperature units (kelvin), so you need to add 273 to each temperature to convert degrees Celsius into Kelvin.

Since you want to find the final pressure you can rearrange the equation to

P2 = P1T2 = (700 mmHg)(273+27) = 700 * 300 = 636.36 mmHg

T1 (273 + 57) 330

The final step is to convert mmHg into the correct units as requested by the problem (psi).

1 psi = 51.7 mmHg

636 mmHg x 1 psi = 12.3 psi

51.7mmHg

You may need to consider sig. figs. This gets you to the approximate answer depending on your instructor's requirements for sig. figs.