Chemistry Acids and Bases Overview

Acids and Bases

• Acids produce hydronium ions (H3O+) when dissolved in water.
• Bases produce hydroxide ions (OH-) when dissolved in water.
• Acid-base reactions involve the transfer of protons (H+).
• Amphoteric substances can act as both acids and bases.

Brønsted-Lowry Theory

• A Brønsted-Lowry acid is a proton (H+) donor.
• A Brønsted-Lowry base is a proton (H+) acceptor.
• A conjugate acid-base pair is formed when an acid donates a proton to a base.
• The conjugate acid is formed by adding a proton to the base.
• The conjugate base is formed by removing a proton from the acid.

pH and pOH

• pH is a measure of the acidity of a solution.
• pH is calculated as the negative logarithm of the hydronium ion concentration: pH = -log[H3O+].
• pOH is a measure of the basicity of a solution.
• pOH is calculated as the negative logarithm of the hydroxide ion concentration: pOH = -log[OH-].

Strength of Acids and Bases

• Strong acids and strong bases dissociate completely in water.
• Weak acids and weak bases dissociate partially in water.

Buffer Solutions

• Buffer solutions resist changes in pH when small amounts of acid or base are added.
• Buffer solutions consist of a weak acid and its conjugate base.
• Buffer capacity is the maximum amount of acid or base that can be added before the buffer stops working.

Ion Product of Water (Kw)

• Kw is the equilibrium constant for the autoionization of water.
• At room temperature, Kw has a value of 1.0 x 10^-14.
• Kw = [H3O+][OH-] = 1.0 x 10^-14.

Polyprotic Acids

• Diprotic acids can donate two protons (H+).
• Triprotic acids can donate three protons (H+).
• Monoprotic acids can donate only one proton (H+).