Write a chemical equation that illustrates the autoionization of water.

Verified step by step guidance

1. Identify the process of autoionization of water, which involves water molecules reacting with each other to form ions.
2. Write the chemical formula for water: \( \text{H}_2\text{O} \).
3. Recognize that in autoionization, one water molecule donates a proton (\( \text{H}^+ \)) to another water molecule.
4. Write the chemical equation for the autoionization: \( 2\, \text{H}_2\text{O}(l) \rightleftharpoons \text{H}_3\text{O}^+(aq) + \text{OH}^-(aq) \).
5. Understand that this equilibrium process is essential for the concept of pH and the self-ionization constant of water, \( K_w \).

Key Concepts

Autoionization of Water

Autoionization of water refers to the process where two water molecules interact to produce hydronium (H3O+) and hydroxide (OH-) ions. This reaction is essential in understanding the behavior of water as both an acid and a base, and it establishes the foundation for the pH scale, which measures the acidity or basicity of solutions.

Chemical Equations

A chemical equation is a symbolic representation of a chemical reaction, showing the reactants and products along with their respective quantities. In the case of the autoionization of water, the equation is represented as 2 H2O ⇌ H3O+ + OH-, indicating that water can dissociate into its ionic components in a reversible manner.

Equilibrium in Chemical Reactions

Equilibrium in chemical reactions occurs when the rates of the forward and reverse reactions are equal, resulting in constant concentrations of reactants and products. For the autoionization of water, this equilibrium is crucial as it determines the concentrations of H3O+ and OH- ions in pure water, which are both 1.0 x 10^-7 M at 25°C, leading to a neutral pH of 7.