Re: Why does cold water contain more dissolved oxygen than warm water?

Lauren,

If you fill a glass with tap water and place it on the table, within a 
short time, the oxygen that was present in the water while it was in the 
tap and the oxygen from the atmosphere will equilibriate and result in a 
steady concentration of oxygen in the glass.  This is because oxygen as a 
gas will dissolve into and at the same time escape from the glass of 
water. The concentration of oxygen in the atmosphere ensures that there 
is enough of it to dissolve some in the glass of water.  This steady 
concentration of oxygen in the glass of water is so because the rate of 
escape from the water is matched with the rate of dissolving into the 
water at the room temperature.  If you increase the room temperature the 
rate of escape of oxygen increases.  The result is that after a short while 
a new steady concentration of oxygen is set in. This time there is less 
oxygen in the water.  Increasing the temperature of a system, in this case a
glass of water, increases the kinetic energy of the molecules in it.  For stable
gases, increasing the temperature means making its molecules increase 
the speed at which they move, making them want to escape the system or 
solution into which they are dissolved.

Hope this helps