Question

why are aerated water bottle kept under water during summer

Answer 1

Aerated water bottle contain excess dissolved oxygen and other minerals which might get lost when comes in the presence of light.

As we move to higher altitude, the atmospheric pressure decreases, therefore balloon can easily expand to large volume.

In summer due to hot weather condition, the air inside the tyre expands to large volume due to heat as compared to winter therefore inflated to lesser pressure in summer.

Answer 2

In summer, the solubility of the gas inwater is likely to decrease because the rise in temperature decreases the solubility. Thus, in summer, more of gas will be present above the liquid surface in the glass bottle. ... To avoid this, the bottles are kept under water.