Question

What is the molar concentration of oxygen in water at 25°C for a partial pressure of 1.0 atm (
`K_H` = 1.3 x 10⁻³ mol/Latm) a. 7.2 x 10⁻⁴b. 1.3 x 10⁻³ M c. 7.7 x 10⁴d. 1.3 x 10⁻⁵

Answer 1

Answer : The correct option is, (b)
`1.3* 10^(-3)M`

Explanation :

According to the Henry's law:

`C_(O_2)=k_H* p_(O_2)`

where,

`C_(O_2)` = molar concentration of
`O_2` = ?

`p_(O_2)` = partial pressure of
`O_2` = 1.0 atm

`k_H` = Henry's law constant =
`1.3* 10^(-3)mole/L.atm`

Now put all the given values in the above formula, we get:

`C_(O_2)=(1.3* 10^(-3)mole/L.atm)* (1.0atm)`

`C_(O_2)=1.3* 10^(-3)mole/L=1.3* 10^(-3)M`

Therefore, the molar concentration of oxygen in water is,
`1.3* 10^(-3)M`