Question

If the gas inside the flask is cooled so that its pressure is reduced from 797.3 torr to a value of 715.7 torr what will be the height of the mercury in the open-end arm? (hint: the sum of the heights in both arms must remain constant regardless of the change in pressure.)

Answer 1

The differential pressure is
797.9 - 715.7 = 82.2 torr = 138815.25 Pa
The height of the mercury in the open-end arm is calculated using
ΔP = ρgh
The density of mercury is 13560 kg/m3
The height of the mercury is
138815.25 Pa = 13560 kg/m3 (9.81 m/s2) h
h = 1.04 m