Question

The partial pressure of in your lungs varies from 25 mm Hg to 40 mm Hg. What mass of can dissolve in 1.0 L of water at 25 °C if the partial pressure of is 39 mm Hg?

Answer 1

The question is incomplete. The complete question is:

The partial pressure of $O_2$ in your lungs varies from 25 mm Hg to 40 mm Hg. What mass of $O_2$  can dissolve in 1.0 L of water at 25 degree Celsius if the partial pressure of $O_2$ is 40 mm Hg.

Answer: $2.12\times 10^{-3}g$  

Explanation:

Henry's law states that the amount of gas dissolved or molar solubility of gas is directly proportional to the partial pressure of the liquid.

To calculate the molar solubility, we use the equation given by Henry's law, which is:

$C_{O_2}=K_H\times p_{O_2}$

where,

$K_H$ = Henry's constant = $1.30\times 10^{-3}mol/Latm$

$p_{O_2}$ = partial pressure = 39 mm Hg =  0.051 atm  (760mmHg=1atm)

Putting values in above equation, we get:

$C_{O_2}=1.30\times 10^{-3}mol/Latm\times 0.051atm\\\\C_{O_2}= 6.63\times 10^{-5}mol/L$

$C_{O_2}=6.63\times 10^{-5}mol/L\times 32g/mol=2.12\times 10^{-3}g$

Hence, $2.12\times 10^{-3}g$  of $O_2$ can dissolve in 1.0 L of water at 25 °C if the partial pressure of is 39 mm Hg