Answer : The concentration of water vapor in a sample of air is, [tex]1.2\times 10^3ppm[/tex]
Explanation : Given,
Partial pressure of water = 0.91 torr
The total pressure of air = 735 torr
Parts per million (ppm) : It is defined as the mass of a solute present in one million [tex](10^6)[/tex] parts by the mass of the solution.
Now we have to calculate the concentration of water vapor in a sample of air.
[tex]\text{Concentration of water vapor}=\frac{\text{Partial pressure of water}}{\text{Total pressure of air}}\times 10^6[/tex]
Now put all the given values in this formula, we get concentration of water vapor in a sample of air.
[tex]\text{Concentration of water vapor}=\frac{0.91torr}{735torr}\times 10^6=2.1\times 10^3ppm[/tex]
Therefore, the concentration of water vapor in a sample of air is, [tex]1.2\times 10^3ppm[/tex]