91Ó°ÊÓ

Molarity is defined as the number of moles per litre solution.

Solubility is defined as the maximum amount of substance that will dissolve in a given amount of solvent at a specific temperature.

The density of a substance is its mass in per unit volume.

It is given that the solubility and density of O₂change with change in temperature.

Given solubility = $\frac{(14.5mg O_2)}{(1 kg H_{2}O)}=\frac{(14.5mg O_2)}{({10}^{6}mg H_{2}O)}$

Given density of water =$\frac{(0.99987 g)}{mL}=\frac{0.99987g}{({10}^{-3} L)}$

By using all the above factors molarity of oxygen can be calculated as follows

At 40⁰C given solubility =$\frac{(6.04 mg O_2)}{(1 kg{H}_{2}O)}=\frac{(6.04 mg O_2)}{({10}^6 mg H_{2}O)}$

Density of water = $\frac{0.99224g}{mL}=\frac{0.99224g}{{10}^{-3}L}$

By using all the above factors molarity of oxygen can be calculated as follows

$$\begin{gathered} molarityof{O}_2=\frac{6.40mg{O}_2}{{10}^{6}mg{H}_{2}O}×\frac{1mol{O}_2}{32g{O}_2}×\frac{0.99224g}{{10}^{-3}L} \\ =1.87×{10}^{-4}mol/L \end{gathered}$$