# How to Calculate Pressure of Enclosed Gas Using Manometer Reading

## Question:

If the atmospheric pressure is 0.995 atm, what is the pressure of the enclosed gas if the manometer reads 30 cm of mercury?

A. 0.765 atm

B. 1.025 atm

C. 1.235 atm

D. 1.500 atm

**Final answer:**

## Answer:

To find the pressure of the enclosed gas, convert the manometer reading from cm Hg to atm using the conversion factor 1 atm = 76 cm Hg. Then, add the converted manometer reading to the atmospheric pressure to get the pressure of the enclosed gas.

Explanation: To determine the pressure of the enclosed gas, we need to convert the manometer reading from centimeters of mercury (cm Hg) to the same unit as atmospheric pressure. Atmospheric pressure is given in atm, so we can use a conversion factor to convert cm Hg to atm. The conversion factor is 1 atm = 76 cm Hg.

Thus, the manometer reading of 30 cm Hg can be converted to atm by dividing it by 76. So, 30 cm Hg / 76 = 0.395 atm. To find the pressure of the enclosed gas, we simply add the atmospheric pressure and the converted manometer reading: 0.995 atm + 0.395 atm = 1.39 atm.

Therefore, the pressure of the enclosed gas is approximately 1.39 atm.