Hydrogen gas is trapped by water displacem ent in a test tube at 25 o C and left to sit until vapor -liquid equilibrium is reached. The total pressure of the trapped gas in th e test tube is 102.0 kPa. What pressure is exerted by the hydrogen gas that was trapped over water?

Therefore, the pressure exerted by the hydrogen gas that was trapped over water is 108.8 kPa

Explanation:

The law of partial pressure by Dalton, in a mixture of gases which do not react chemically together, the total pressure is equal to the sum of the partial pressures of the individual gases.

According to this law, the total pressure exerted by the gases above the displaced water is equal to the sum of the partial pressure of water vapor and the partial pressure of hydrogen gas: Ptotal = pH₂ + pH₂O

Therefore, pH₂ = Ptotal - pH₂O

Vapor pressure of water at 37°C = 3.17 kPa; Ptotal = 102.0 kPa

pH₂ = (102.0 - 3.17) kPa

pH₂ = 98.8 kPa

Therefore, the pressure exerted by the hydrogen gas that was trapped over water is 108.8 kPa