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What are the differences between an acid and a base?
Posted March 13, 2024
Answer
Basis of differentiation | Acid | Base |
Definition | An acid is a substance with a pH value lower than 7 when present in an aqueous solution | A base is a substance with a pH value higher than 7 when present in an aqueous solution |
Arrhenius theory | An acid is a substance that increases the concentration of H+ (hydrogen ions) in an aqueous medium | A base is a substance that increases the concentration of hydroxide ions (OH–) in an aqueous medium |
Bronsted-Lowry theory | An acid is a substance that donates protons | A base is a substance that accepts protons |
Lewis theory | An acid is an electron pair acceptor – it accepts a pair of electrons from a covalent chemical bond | A base is an electron pair donor – it donates a pair of electrons |
Dissociation | An acid release H+ (hydrogen ions) when dissolved in water | A base releases OH– (Hydroxide ions) when dissolved in water |
Taste | Is Sour | Is bitter |
Odor | Has a burning odor | Is odorless except for ammonia |
Touch sensation | Is sticky to the touch | Is slippery to the touch |
pH value | The pH value of an acid may range from 1 to 7 | The pH value of a base may range from 7 to 14 |
Ionization | An acid forms hydronium ions on ionization | A base forms hydroxyl ions on ionization |
Neutralization | Can be neutralized using a base | Can be neutralized using an acid |
Reaction with litmus paper | An acid will turn blue litmus red but has no reaction with red litmus | A base will turn red litmus blue but has no reaction with blue litmus |
Reaction with Phenolphthalein | An acid remains colorless on adding Phenolphthalein to the solution | A base turns pink on adding Phenolphthalein is the solution |
Strength | The strength of an acid depends on the concentration of hydronium ions | The strength of a base depends on the concentration of hydroxide ions |
Chemical formula | The chemical formula of most acids begins with H, for example, Sulfuric acid (H2SO4), | The chemical formula of most bases ends with OH, for example, Potassium Hydroxide (KOH). |
Examples | Hydrochloric acid (HCl), Sulfuric acid (H2SO4), Nitric acid (HNO3) | Example: Sodium Hydroxide (NaOH), Potassium Hydroxide (KOH), Caesium Hydroxide (CsOH) |
Uses | Acids are used in carbonated drinks, preservatives and fertilizers, as household cleaning agents, for processing leather, and in the manufacture of batteries | Bases are used in the manufacture of gastric medicines such as antacids, toothpaste, soaps, detergents, and paper |