The water having more
Question:

The water having more dissolved $\mathrm{O}_{2}$ is :

1. boiling water

2. water at $80^{\circ} \mathrm{C}$

3. polluted water

4. water at $4^{\circ} \mathrm{C}$

Correct Option: 4,

Solution:

On heating concentration of $\mathrm{O}_{2}$ in water decreases. So boiling water and water at $80^{\circ} \mathrm{C}$ having less $\mathrm{O}_{2}$ concentration. Polluted water also having less $\mathrm{O}_{2}$ concentration. So water at $4^{\circ} \mathrm{C}$ having maximum $\mathrm{O}_{2}$ concentration.