Acid and Base Chart — Table of Acids & Bases

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.

Learn how to use this acid base chartDownload chart.

Table of Acid and Base Strength
Acid       Base    
Strength of Acid Ka Name Formula Formula Name Strength of Base
Strongest Large Perchloric acid HClO4 ClO4- Perchlorate
ion
Weakest
  3.2 * 109 Hydroiodic acid HI I- Iodide  
  1.0 * 109 Hydrobromic acid HBr Br- Bromide  
  1.3 * 106 Hydrochloric acid HCl Cl- Chloride  
  1.0 * 103 Sulfuric acid H2SO4 HSO4- Hydrogen
sulfate ion
 
  2.4 * 101 Nitric acid HNO3 NO3- Nitrate ion  
  -------- Hydronium ion H3O+ H2O Water  
  5.4 * 10-2 Oxalic acid HO2C2O2H HO2C2O2- Hydrogen
oxalate ion
 
  1.3 * 10-2 Sulfurous acid H2SO3 HSO3- Hydrogen
sulfite ion
 
  1.0 * 10-2 Hydrogen sulfate ion HSO4 - SO4 2- Sulfate ion  
  7.1 * 10-3 Phosphoric acid H3PO4 H2PO4- Dihydrogen
phosphate ion
 
  7.2 * 10-4 Nitrous acid HNO2 NO3- Nitrite ion  
  6.6 * 10-4 Hydrofluoric acid HF F- Fluoride ion  
  1.8 * 10-4 Methanoic acid HCO2H HCO2- Methanoate
ion
 
  6.3 * 10-5 Benzoic acid C6H5COOH C6H5COO- Benzoate ion  
Medium 5.4 * 10-5 Hydrogen oxalate ion HO2C2O2- O2C2O2 2- Oxalate ion Medium
  1.8 * 10-5 Ethanoic acid CH3COOH CH3COO Ethanoate
(acetate) ion
 
  4.4 * 10-7 Carbonic acid CO3 2- HCO3- Hydrogen
carbonate ion
 
  1.1 * 10-7 Hydrosulfuric acid H2S HS- Hydrogen
sulfide ion
 
  6.3 * 10-8 Dihydrogen phosphate ion H2PO4 - HPO4 2- Hydrogen
phosphate ion
 
  6.2 * 10-8 Hydrogen sulfite ion HS- SO32- Sulfite ion  
  2.9 * 10-8 Hypochlorous acid HClO ClO- Hypochlorite
ion
 
  6.2 * 10-10 Hydrocyanic acid HCN CN- Cyanide ion  
  5.8 * 10-10 Ammonium ion NH4 + NH3 Ammonia  
  5.8 * 10-10 Boric acid H3BO3 H2BO3- Dihydrogen
carbonate ion
 
  4.7 * 10-11 Hydrogen carbonate ion HCO3 - CO3 2- Carbonate
ion
 
  4.2 * 10-13 Hydrogen phosphate ion HPO4 2- PO4 3- Phosphate
ion
 
  1.8 * 10-13 Dihydrogen borate ion H2BO3- HBO3 2- Hydrogen
borate ion
 
  1.3 * 10-13 Hydrogen sulfide ion HS- 2- Sulfide ion  
  1.6 * 10-14 Hydrogen borate ion HBO3 2- BO3 3- Borate ion  
Weakest --------- water H2O OH- Hydroxide Strongest

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.

Download the Acid & Base Chart

Acid & Base Chart Image 

Acid & Base Chart PDF 

Acids and Bases Chart Download

Acid and Base Chart Downloadable PDF