Ionic product of Water

Water is a weak electrolyte and undergoes selfionistion to a small extent.

“The product of concentrations of  and  ions in water at a particular temperature is known as ionic product of water.” It is designated as .

 ⇌ ;

;;

The value of  increases with the increase of temperature, i.e., the concentration H⁺ and OH^– ions increases with increase in temperature.

The value of  at  is mole/litre. Since pure water is neutral in nature,  ion concentration must be equal to  ion concentration.

 or  or  or 

This shows that at , in 1 litre only  mole of water is in ionic form out of a total of approximately 55.5 moles.

Thus when, ; the solution is neutral

; the solution is acidic

; the solution is basic