Question

What is meant by ionic product of water?

Short answer

Answer: The ionic product of water (Kw) is a measure of the concentration of hydrogen ions (H+) and hydroxide ions (OH-) in water at equilibrium. It is represented by the expression Kw = [H+][OH-]. The ionic product of water helps in understanding the degree of dissociation of water molecules and the acidity or alkalinity of a solution, with a constant value of approximately 1.0 x 10^-14 at 25°C.

Step-by-step solution

Understand water dissociation

Water can undergo a process called dissociation, where a water molecule dissociates or breaks down into ions. In this process, a water molecule (H2O) breaks into a hydrogen ion (H+) and a hydroxide ion (OH-). The dissociation of water can be represented by the following equilibrium reaction: (H2O) ⇌ (H+) + (OH-)

Define ionic product of water

The ionic product of water, also known as the water self-ionization constant (Kw), is a measure of the concentration of hydrogen ions (H+) and hydroxide ions (OH-) in water at equilibrium. It gives an indication of the degree of dissociation of water molecules and helps to understand the acidity or alkalinity of a solution.

Express the ionic product of water mathematically

In order to calculate the ionic product of water, we use the dissociation equation of water and the equilibrium constant expression. The equilibrium constant expression for the dissociation of water is written as follows: Kw= [H+][OH-] Here, Kw is the ionic product of water, [H+] is the concentration of hydrogen ions in a solution at equilibrium and [OH-] is the concentration of hydroxide ions in a solution at equilibrium.

Note the value of the ionic product of water

The value of the ionic product of water (Kw) depends on temperature. At 25°C, the ionic product of water is approximately 1.0 x 10^-14. In summary, the ionic product of water refers to the product of the concentrations of hydrogen ions (H+) and hydroxide ions (OH-) in water at equilibrium, and it is denoted by the constant Kw. It helps to understand the degree of dissociation of water and the acidity or alkalinity of a solution.