15 Facts on HCl + Na2PO4: What, How To Balance & FAQs

Hydrochloric acid is a strong acid. In contrast, sodium phosphate is a salt with a strong base, i.e., sodium hydroxide. Let us study how HCl and Na2PO4 react.

HCl + Na2PO4 react to give salt metathesis reaction. HCl is an aqueous solution of hydrogen chloride. It dissociates readily to give proton and chloride anions. In contrast, sodium phosphate is a dibasic compound. It is an inexpensive, non-toxic compound commonly used for baked goods.

In this article, we will study the type, product, and balancing of the HCl + Na2PO4 reaction.

What is the product of HCl and Na2PO4?

HCl and Na2PO4 react to form sodium chloride and dihydrogen phosphate.

Na2PO4 + 2HCl → 2NaCl + H2PO4

What type of Reaction is HCl + Na2PO4

The HCl + Na2PO4 is a double displacement reaction as the cation and anion of the two ionic compounds exchange bonds to create 2 new compounds with nearby or equivalent bonding affiliations.

How to Balance HCl + Na2PO4

The equations is balanced by a hit-and-trial method as follows. 

  • To balance HCl + Na2PO4 equation, we will balance the number of sodium atoms both in reactant and product side.
  • Na2PO4 + HCl → 2NaCl + H2PO4
  • Now, we will balance the number of chlorine atoms.
  • Na2PO4 + 2HCl → 2NaCl + H2PO4
  • Next, we will balance the oxygen and hydrogen atoms as we can see that the number of hydrogen and oxygen is already balanced.
  • Thus, we can conclude that the above equation is a required balance equation.
  • Na2PO4 + 2HCl → 2NaCl + H2PO4

HCl + Na2PO4 Titration

HCl + Na2PO4 does not undergo titration as no equivalence point is observed during the reaction.

HCl + Na2PO4 Net Ionic Equation

The net ionic equation of HCl + Na2PO4 is PO4-3 + 2H+ → H2PO4. We will follow the following steps to calculate the net ionic equation.

  • To calculate the net ionic equation of HCl + Na2PO4, the balanced equation is written first.
  • Na2PO4 + 2HCl → 2NaCl + H2PO4
  • The total ionic equation for the balanced equation is as follows:
  • 2Na+ + PO4-3 + 2H+ + 2Cl → 2Na+ + 2Cl + H2PO4
  • Hence, the net equation is:
  • PO4-3 + 2H+ → H2PO4

HCl + Na2PO4 Conjugate Pairs

  • The conjugate pair of hydrochloric acid is Cl.
  • There is no conjugate pair of Na2PO4 because of the absence of protons in sodium phosphate.

HCl and Na2PO4 Intermolecular Forces

  • Dipole-dipole intermolecular force is present between the molecule of hydrochloric acid.
  • There is an electrostatic force of attraction between molecules of sodium phosphate.

HCl + Na2PO4 Reaction Enthalpy

The reaction enthalpy data of HCl + Na2PO4 is not available in literature.

Is HCl + Na2PO4 a Buffer Solution

HCl + Na2PO4 is not a buffer solution as it contains strong hydrochloric acid(HCl) and a weak acid salt, sodium phosphate (Na2PO4).

Is HCl + Na2PO4 a Complete Reaction

HCl + Na2PO4 is a complete reaction as no reactant is left at the end of reaction.

Na2PO4 + 2HCl → 2NaCl + H2PO4

Is HCl + Na2PO4 an Exothermic Reaction

The reaction between HCl and Na2PO4 is an exothermic reaction as the value of delta G is negative.

Is HCl + Na2PO4 a Redox Reaction

The HCl + Na2PO4 is not a redox reaction, as the oxidation state of the substrate remains unchanged.

Is HCl + Na2PO4 a Precipitation Reaction

The HCl + Na2PO4 is not a precipitation reaction as no insoluble salt is formed during the reaction.

Na2PO4 + 2HCl → No precipitate

Is HCl + Na2PO4 Irreversible Reaction

The HCl + Na2PO4 is an irreversible reaction as it is a unidirectional reaction thus can not extract the reactants from the products.

Is HCl + Na2PO4 Displacement Reaction

The HCl + Na2PO4 is a displacement reaction because sodium ion displaces the hydrogen ion from hydrochloric acid to form sodium chloride. And the phosphate ion displaces chloride ion from hydrochloric acid to form phosphoric acid.

Na2PO4 + 2HCl → 2NaCl + H2PO4


Sodium phosphate (Na2PO4), reacts with hydrochloric acid to give a double displacement reaction forming sodium chloride (NaCl) and dihydrogen phosphate (H2PO4). It is an irreversible reaction, and the oxidation state of the substrate remains unchanged during the reaction.

Leena Raswant

Hi, I am Leena Raswant, a chemistry postgraduate. I thrive on challenges and continually specified goals. I aim to learn, unlearn, relearn and spread my knowledge in the best possible ways. Currently, I am working as a chemistry educator and a freelance writer. You can connect with me on Linkedin: https://www.linkedin.com/in/leena-raswant-62b285186/

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