Answer :
When gases are collected over water, the total pressure in the container is the sum of the partial pressures of the gas of interest and the water vapor. Mathematically, this is expressed as
[tex]$$
P_{\text{total}} = P_{\text{gas}} + P_{\text{H}_2O}.
$$[/tex]
To find the partial pressure of the hydrogen gas, we rearrange the equation:
[tex]$$
P_{\text{gas}} = P_{\text{total}} - P_{\text{H}_2O}.
$$[/tex]
Given:
- The total pressure [tex]$P_{\text{total}} = 97.1 \, \text{kPa}$[/tex],
- The vapor pressure of water [tex]$P_{\text{H}_2O} = 3.2 \, \text{kPa}$[/tex],
we substitute these values into the equation:
[tex]$$
P_{\text{gas}} = 97.1 \, \text{kPa} - 3.2 \, \text{kPa} = 93.9 \, \text{kPa}.
$$[/tex]
Thus, the partial pressure of the hydrogen gas is
[tex]$$
\boxed{93.9 \, \text{kPa}},
$$[/tex]
which corresponds to option A.
[tex]$$
P_{\text{total}} = P_{\text{gas}} + P_{\text{H}_2O}.
$$[/tex]
To find the partial pressure of the hydrogen gas, we rearrange the equation:
[tex]$$
P_{\text{gas}} = P_{\text{total}} - P_{\text{H}_2O}.
$$[/tex]
Given:
- The total pressure [tex]$P_{\text{total}} = 97.1 \, \text{kPa}$[/tex],
- The vapor pressure of water [tex]$P_{\text{H}_2O} = 3.2 \, \text{kPa}$[/tex],
we substitute these values into the equation:
[tex]$$
P_{\text{gas}} = 97.1 \, \text{kPa} - 3.2 \, \text{kPa} = 93.9 \, \text{kPa}.
$$[/tex]
Thus, the partial pressure of the hydrogen gas is
[tex]$$
\boxed{93.9 \, \text{kPa}},
$$[/tex]
which corresponds to option A.