Phosphoric Acid and Sodium Hydroxide (First Neutralization)
H3PO4 + NaOH → NaH2PO4 + H2O
Overview
The first neutralization step of the triprotic phosphoric acid produces monosodium phosphate and water. Phosphoric acid has three ionizable protons with Ka1 = 7.1 × 10⁻³, Ka2 = 6.3 × 10⁻⁸, and Ka3 = 4.2 × 10⁻¹³. Each successive proton is progressively harder to remove.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Phosphoric Acid H₃PO₄ | 1 | (aq) |
| Reactant | Sodium Hydroxide NaOH | 1 | (aq) |
| Product | Water H₂O | 1 | (l) |
Everyday Example
Monosodium phosphate is used as a leavening agent in baking and as an emulsifier in processed cheese.
Industrial Importance
Monosodium phosphate is used in food processing, water treatment, and as a buffering agent in pharmaceutical formulations.
Properties
- Type
- Acid-Base
- Reversible
- No
- Energy
- Exothermic
- ΔH
- -56.0 kJ/mol
Related Reactions
Acetic Acid and Sodium Acetate Buffer System
Acetic Acid and Sodium Hydroxide Neutralization
Acetic Acid Dissociation in Water
Aluminum Chloride and Chloride Ion (Lewis Acid-Base)
Aluminum Hydroxide as Amphoteric Acid with NaOH
Aluminum Hydroxide as Amphoteric Base with HCl
Ammonia and Ammonium Chloride Buffer System
Ammonia and Hydrochloric Acid
Ascorbic Acid and Sodium Hydroxide
Barium Hydroxide and Ammonium Thiocyanate (Endothermic)
Frequently Asked Questions
What is the equation for Phosphoric Acid and Sodium Hydroxide (First Neutralization)?
The balanced equation is: H₃PO₄ + NaOH → NaH₂PO₄ + H₂O.
What type of reaction is Phosphoric Acid and Sodium Hydroxide (First Neutralization)?
Phosphoric Acid and Sodium Hydroxide (First Neutralization) is a acid-base reaction.
Is Phosphoric Acid and Sodium Hydroxide (First Neutralization) exothermic or endothermic?
Phosphoric Acid and Sodium Hydroxide (First Neutralization) is exothermic (releases energy). The enthalpy change (ΔH) is -56.0 kJ/mol.