# A vessel collects Gas B over water at 35 C. Within the container, the total pressure is 110 kPa. How do you calculate the partial pressure of Gas B if the water vapor pressure at 35°C is 5.6 kPa?

Nov 29, 2016

Well the partial pressures are additive, so......

#### Explanation:

${P}_{\text{container"=P_"gas B"+P_"SVP}}$.

Here ${P}_{\text{SVP}}$ is the so-called $\text{saturated vapour pressure (of water)}$. ${P}_{\text{SVP}}$ is usually tabulated, and (typically) quoted in units of $m m \cdot H g$; it varies according to temperature. Are you sure your values are correct?

So ${P}_{\text{gas B"=P_"container"-P_"SVP}}$

$=$ $\left(110 - 5.6\right) \cdot k P a = 104.4 \cdot k P a$