Question

what is effect of temperature on pH.

Answer 1

The pH at room temperature is ~7 meaning there are about 10-7 moles of H+ per liter of water at roomtemperature. As the temperatureincreases, the ability of water to ionize in this way increases and so the concentration of H+ in solution will increase (and hence the pH will drop).

Answer 2

pH decrease with the increase in temperature