Question

Use the data from Table 15.1, together with Le Châtelier’s principle, to decide whether the autoionization of water is exothermic or endothermic.

Short answer

Autoionization of water is an endothermic reaction.

Step-by-step solution

Understanding exothermic and endothermic reaction

An exothermic process releases heat, causing the temperature of the immediate surroundings to rise. An endothermic process absorbs heat and cools the surroundings.”

Analysing table Step 2: Analysing table

The value ofincreases with increase in the temperature.

 Explanation

Water is able to auto-ionize into $H_{3}O+1$and$O{H}^{-1}$ in an equilibrium reaction. If we increases the temperature$K_w$ increases and the equilibrium shifts towards the products. Because an increase in temperature favours the endothermic side ,we conclude that the autoionization of water is endothermic.