What is the pressure (in atmospheres) of the sample of gas trapped in the closed-tube mercury manometer shown below if h = 23.6 cm?

Given:

Height of the mercury manometer, h = 23.6 cm

To determine:

The pressure of gas trapped in the closed-tube mercury manometer

Explanation:

In the case of a closed tube mercury manometer, the pressure of the gas is equal to the height difference of the mercury levels in the two arms of the manometer.

i. e. P (gas) = P (h)

in this case, h = 23.6 cm = 236 mm

i. e. Pgas = 236 mmHg

Since, 1 atm = 760 mmHg

The corresponding Pgas (atm) = 236 mmHg * 1 atm/760 mmHg = 0.311 atm

Ans: The pressure of the gas is 0.311 atm