Relative Strength of Acids & Bases

Use this acids and bases chart to find the relative strength of the most common acids and bases. This acid-base chart includes the Ka value for reference along with the chemical's formula and the acid’s conjugate base. The acid and base chart is a reference table designed to make determining the strength of acids and bases simpler. This chart is ideal for use in the lab or in the classroom.

Table of Acid and Base Strength

How to Use the Acid & Base Chart

Read these instructions to learn how to use this acids and bases chart. The table lists the Ka values and the strength of each acid and base.

  1. Strong acids are listed at the top left-hand corner of the table and have Ka values >1
  2. Acids with a Ka value less than one are considered weak and get weaker as we move to the bottom of the table.
  3. The strong bases are listed at the bottom-right of the table and get weaker as we move to the top of the table.

Conjugate Acid-Base Pairs

In this chart, the strongest acids are at the top left, and the weakest bases are at the top right. The conjugate base of a strong acid is a weak base; therefore, the conjugate acid of a strong base is a weak acid.

Acid-Base Pairs and Buffer Chemistry

A buffer solution contains a weak acid and its conjugate base or a weak base and its conjugate acid. Buffers work by reacting with a base or acid to control the pH of a solution.

Download the Acid & Base Chart