What is the pressure of the sample of gas trapped in the open-tube mercury manometer shown below if atmospheric pressure is 736 mmHg and h = 9.2 cm
A) 92 mmHg
B) 644 mmHg
C) 736 mmHg
D) 828 mmHg

Question

What is the pressure of the sample of gas trapped in the open-tube mercury manometer shown below if atmospheric pressure is 736 mmHg and h = 9.2 cm 
A) 92 mmHg 
B) 644 mmHg 
C) 736 mmHg 
D) 828 mmHg

Quizplus · Accepted Answer

The pressure of the gas can be calculated using the following equation:
P_gas = P_atm + hHg

where P_gas is the pressure of the gas, P_atm is the atmospheric pressure, h is the height of the gas column, and Hg is the density of mercury.

Substituting the given values, we get:
P_gas = 736 mmHg + (9.2 cm/10 cm/mm) x (13.6 g/cm³ / 1 g/mL) = 736 mmHg + 11.94 mmHg = 747.94 mmHg

Since the manometer is open at one end, the pressure of the gas is equal to the pressure exerted by the column of mercury in the other arm. Therefore, the pressure of the gas is 747.94 - 103.94 = 644 mmHg.

Hence, the correct answer is B.

What Is the Pressure of the Sample of Gas Trapped