Will the concentration of `H_(3)O^(+)` ions in pure water at `0^(@)C` be more than or less than that at `4^(@)C`?

Explanation

Ionisation of water is an endothermic process: `[2H_(2)O(l) hArr H_(3)O^(+)(aq)+OH^(-)(aq)]`. Hence, with rise in temperature, the ionic product of water `(K_(w))` increases. Therefore, `K_(w)(4^(@)C) gt K_(w)(0^(@)C)`. In pure water, `[H_(3)O^(+)]=sqrt(K_(w))`. since, `K_(w)(4^(@)C) gt K_(w)(0^(@)C)`, the concentration of `H_(3)O^(+)` ions in pure water at `4^(@)C` will be higher than that at `0^(@)C`.