In neutralization reactions, salt and water are formed from acids and bases. One mole of H+ produced from the acid combines with one mole of OH– produced from the base. It means that an equal amount of acidic ions is neutralized by an equal amount of basic ions.
A reaction in which an acid and a base react to form salt and result in the combination of H+ and OH– to produce water is called a neutralization reaction.
Acid + Base → Salt + Water
HA(aq) + BOH(aq) → BA(aq) + H2O
Enthalpy of Neutralization
The heat evolved when one mole of H2O is formed by complete neutralization of an acid with a base at S.T.P. is called standard enthalpy of neutralization. It is represented by ∆Hno.
The Enthalpy of neutralization of strong acid and strong base is always -57.3 kJ/mol.
Strong Acids
- Sulphuric acid (H2SO4)
- Nitric acid (HNO3)
- Hydroiodic acid (HI)
- Hydrobromic acid (HBr)
- Hydrochloric acid (HCl)
- Perchloric acid (HClO4)
All other inorganic and organic acids are weak acids.
Strong Bases
- Cesium hydroxide (CsOH)
- Rubidium hydroxide (RbOH)
- Potassium hydroxide (KOH)
- Sodium hydroxide (NaOH)
- Lithium hydroxide (LiOH)
- Barium hydroxide (Ba(OH)2
- Strontium hydroxide Sr(OH)2
- Calcium hydroxide Ca(OH)2
All other inorganic and organic bases are weak bases.
Related content
Neutralization Reactions
Strong Acid vs Strong Base
Consider a reaction between strong acid, hydroiodic acid (HI), and a strong base, cesium hydroxide (CsOH).
HI(g) → H+(aq) + l– (aq)
CsOH(s) → Cs+(aq) + OH–(aq)
Overall reaction;
H+(aq) + l–(aq) + Cs+(aq) + OH–(aq) →l–(aq) + Cs+(aq) + H2O
When spectator ions l–(aq) and Cs+(aq) are removed, the net equation is only the combination of H+ and OH– to form H2O. Therefore, the neutralization of strong acid and strong base is the formation of H2O from H+ and OH–. That is why the enthalpy of neutralization of strong acid and strong base is always -57.3kJ/mol.
H+(aq) + OH–(aq) → H2O
∆Hno =-57.3kJ/mol
At 25 °C, when H+ from strong acid completely neutralizes the OH– from a strong base, it results in the formation of a neutral solution, and the pH of this neutralized solution is always 7.
Weak Acid vs Strong Base
A strong base is completely ionized in water to produce an excess OH–, while weak acid is partially ionized to produce limited H+. The hydroxyl ion (OH–) from a strong base neutralizes the acidic ion (H+) from a weak acid. After neutralization (OH–) ions are still present in the solution due to their excess concentration. This results in the pH of the resultant solution being greater than 7 (pH>7).
Strong Acid vs Weak Base
A strong acid is completely ionized in water to produce an excess (H+), while the weak base is partially ionized to produce limited (OH–). The (H+) from a strong acid neutralizes the (OH–) from a weak base. After neutralization (H+) ions are still present in the solution due to their excess concentration. This results in the pH of the solution being lesser than 7 (pH<7).
Related content
- Characteristics of Acids and Bases
- Types of Chemical Reactions and their Identifications
- Lewis Acid vs Lewis Base: Comparison with Examples
Weak Acid vs Weak Base
When weak acid and weak base combine three different conditions are possible.
- If [Ka > Kb], the solution is acidic (pH<7).
- If [Ka < Kb], the solution is basic (pH>7).
- If [Ka = Kb], the solution is neutral (pH=7).
Concepts Berg
What is an Acid Base Neutralization Reaction?
An acid–base neutralization reaction is a chemical reaction in which an acid and a base form a salt and water and neutralize one another‘s properties.
Acid + Base → Salt + Water
HA(aq) + BOH(aq) → BA(aq) + H2O
What are the products of a neutralization reaction?
The products of a neutralization reaction are salt and water.
Acid + Base → Salt + Water
Are neutralization reactions reversible?
Neutralization reactions are generally considered to be irreversible reactions, meaning that once the acid and base have reacted to form salt and water, they cannot be easily separated or converted back into the original acid and base.
However, some neutralization reactions can be reversible under certain conditions. Examples of reversible neutralization reactions are buffer solutions, which are solutions that can resist changes in pH when small amounts of acid or base are added.
How does a neutralization reaction help in the treatment of soil?
A neutralization reaction helps treat soil by balancing the pH levels. When the soil is too acidic, it can lead to nutrient deficiencies and inhibit the growth of plants. Neutralization reactions can help reduce the acidity of the soil by converting acids into salts, thus restoring the pH levels to a more suitable range for plant growth.
What is a neutralization reaction example?
HCl + NaOH → NaCl + H2O
HNO3 + KOH → KNO3 + H2O
H2SO4 + Mg(OH)2 → MgSO4 + H2O
How do you identify neutralization reactions?
- The acid and base neutralize each other and form salt and water.
- The acid and base neutralize each other, resulting in a solution with a neutral pH of 7.
- The evolution of heat may accompany the reaction.
- The reaction may produce a precipitate indicating the formation of an insoluble salt.
- The reaction may evolve gas.
What are 2 common neutralization reactions?
What are the 2 products of neutralization?
Acid + Base → Salt + Water
- Salt
- Water
What is called neutralization?
Neutralization is a chemical reaction in which an acid and a base react to form salt and water. It is a redox reaction in which the positive and negative charges of the reactants are equalized.
References links
- An article (chem.libretexts.org)
