Question

Suppose you are collecting a gas over water at 23 oC and obtain a pressure reading of 785.8 mm Hg. If the vapor pressure of water is 21.1 mm Hg at the collection temperature, what is the pressure of the collected gas

Answer 1

Answer:

764.7 mmHg

Explanation:

Step 1: Given data

• Total pressure of the gaseous mixture (P): 785.8 mmHg

• Partial pressure of water vapor (pH₂O): 21.1 mmHg

• Partial pressure of the gas collected (pGas): ?

Step 2: Calculate the partial pressure of the gas collected

The total pressure of the gaseous mixture is equal to the sum of the gas collected and the water vapor.

P = pH₂O + pGas

pGas = P - pH₂O

pGas = 785.8 mmHg - 21.1 mmHg = 764.7 mmHg