15 Facts on H2SO4 + NaOH: What, How To Balance & FAQs

H₂SO₄, also known as oil of vitriol is used in petroleum refining. Whereas NaOH, commonly known as caustic soda, is used to produce soap. Let us learn how H₂SO₄ and NaOH react.

H₂SO₄ combines with NaOH to give a salt metathesis reaction. H₂SO₄, aka sulphuric acid, is known as the king of acids. It dissociates to give two protons and a sulphate ion. In contrast, NaOH, aka sodium hydroxide, is a strong base. It dissociates to give sodium and hydroxide ions, respectively. 

In this article, we will learn about the type, product, and balancing of the H₂SO₄ + NaOH reaction.

What is the Product of H₂SO₄ and NaOH?

Na₂SO₄ (Sodium Sulphate) and H₂O (Water) are formed during the reaction of H₂SO₄ and NaOH.

NaOH + H₂SO₄ → Na₂SO₄ + H₂O

What type of Reaction is H₂SO₄ + NaOH?

H₂SO₄ + NaOH is a neutralisation reaction as an acid reacts with a base to form salt and water.

NaOH + H₂SO₄ → Na₂SO₄ + H₂O

How to Balance H₂SO₄ + NaOH?

We can balance the equation by hit-and-trial method using the following steps.

• H₂SO₄ + NaOH → Na₂SO₄ + H₂O
• Foremost, we will compare the reactant elements with the product elements.

Reactant Side	Product Side
1 Sodium atom from Sodium Hydroxide.	2 Sodium atoms from Sodium Sulphate.
1 Oxygen atom from Sodium Hydroxide.	1 Oxygen atom from Water.
3 Hydrogen atoms from Sodium Hydroxide and Sulphuric Acid.	2 Hydrogen atoms from Water.
1 Sulphate unit from Sulphuric Acid.	1 Sulphate unit from Sodium Sulphate.

• First, balance the sodium atom followed by the sulphate unit, oxygen and hydrogen.
• Put stoichiometric coefficient 2 in front of NaOH from the reactant side to balance the sodium atoms.
• H₂SO₄ + NaOH → Na₂SO₄ + H₂O
• Again compare the reactant atoms with the product atoms.

Reactant Side	Product Side
2 Sodium atoms from Sodium Hydroxide.	2 Sodium atoms from Sodium Sulphate.
2 Oxygen atoms from Sodium Hydroxide.	1 Oxygen atom from Water.
4 Hydrogen atoms from Sodium Hydroxide and Sulphuric Acid.	2 Hydrogen atoms from Water.
1 Sulphate unit from Sulphuric Acid.	1 Sulphate unit from Sodium Sulphate.

• Put stoichiometric coefficient 2 in front of H₂O from the product side to balance the hydrogen and oxygen atoms.
• H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O
• Again compare the reactant atoms with the product atoms.

Reactant Side	Product Side
2 Sodium atoms from Sodium Hydroxide.	2 Sodium atoms from Sodium Sulphate.
2 Oxygen atoms from Sodium Hydroxide.	2 Oxygen atoms from Water.
4 Hydrogen atoms from Sodium Hydroxide and Sulphuric Acid.	4 Hydrogen atoms from Water.
1 Sulphate unit from Sulphuric Acid.	1 Sulphate unit from Sodium Sulphate.

• We can see that the reactant atoms are equivalent to the product atoms. Thus the equation mentioned above is the required balanced equation.
• H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

H₂SO₄ + NaOH Titration

H₂SO₄ + NaOH undergo titration to determine the concentration of sulphuric acid by neutralising it with a standard solution of sodium hydroxide. The process is explained below.

Apparatus Used

• Beaker
• Test tube
• Pipette
• Burette
• Stand
• Burette clamp
• Glass funnel
• Unknown Sulphuric Acid Solution
• Known Sodium Hydroxide Solution
• Phenolphthalein

Indicator

Phenolphthalein is used as an indicator.

Procedure

• Foremost, rinse the burette with a known sodium hydroxide solution, fill it to the tip, and record the initial recording of the burette as 0.
• Then carefully suck the unknown hydrochloric acid solution using a pipette and transfer it to a titration flask.
• Add a slight phenolphthalein to the titration flask.
• Pour the known sodium hydroxide solution from the burette into the titration flask till it changes pink in colour.
• Note the reading and repeat the steps.
• To calculate the normality of titrant we will use the following formulae:
• N₁V₁ = N₂V₂
• The mass of substance can be determined after finding the normality of titrant by using the formulae:
• Mass of substance = Equivalent Weight X Normality X Volume / 1000

H₂SO₄ + NaOH Net Ionic Equation

The net ionic equation of H₂SO₄ + NaOH is

2OH^– + 2H^{+ –} → 2H₂O.

To derive the net ionic equation we will follow the following steps.

• First, we will write the balanced equation to find the net ionic equation.
• 2NaOH (aq) + H₂SO₄ (aq) → Na₂SO₄ (aq) + 2H₂O (aq)
• Thus, the total ionic equation for the above balanced equation is:
• 2Na⁺ + 2OH^– + 2H⁺ + SO₄^2- → 2Na⁺ + SO₄^2- + 2H₂O
• The 2Na⁺ and SO₄^2- are present in reactant as well as product.
• Hence, the final net equation will be:
• 2OH^– + 2H^{+ –} → 2H₂O

H₂SO₄ + NaOH Conjugate Pairs

• The conjugate base of H₂SO₄ is a sulphate ion (SO₄^2-) ion.
• The conjugate acid of NaOH is a water molecule (H₂O).

H₂SO₄ and NaOH Intermolecular Forces

H₂SO₄ and NaOH contain Van der Waal force, dipole-dipole, hydrogen bonding and electrostatic intermolecular force of attraction.

H₂SO₄ + NaOH Reaction Enthalpy

H₂SO₄ + NaOH has 57.3 kJ/mol enthalpy of neutralisation at standard conditions.

Is H₂SO₄ + NaOH a Buffer Solution

H₂SO₄ + NaOH is not a buffer solution, as H₂SO₄ is a strong acid, NaOH is a strong base, and a buffer is formed by combining a weak acid with its conjugate base.

Is H₂SO₄ + NaOH a Complete Reaction

H₂SO₄ + NaOH is a complete reaction, as no reactant is left during the reaction.

Is H₂SO₄ + NaOH an Exothermic Reaction

H₂SO₄ + NaOH is an exothermic reaction as a large amount of heat is released during the reaction, and the value of delta G is highly negative. 

Is H₂SO₄ + NaOH a Redox Reaction

H₂SO₄ + NaOH is not a redox reaction as the oxidation state of atoms remains constant. 

Is H₂SO₄ + NaOH a Precipitation Reaction

H₂SO₄ + NaOH is not a precipitation reaction, as no substance is deposited at the end of the reaction.

Is H₂SO₄ + NaOH Irreversible Reaction

H₂SO₄ + NaOH is an irreversible reaction as the reaction is unidirectional.

Is H₂SO₄ + NaOH Displacement Reaction

H₂SO₄ + NaOH is a displacement reaction as the sodium ion of the reactant exchanges its site from the hydrogen of sulphuric acid to form sodium sulphate, and the hydroxide ion exchanges its position from the sulphate ion of sulphuric acid to form water.

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

Conclusion

H₂SO₄ + NaOH is a neutralisation reaction. In it an acid-base reaction occurs leading to the formation of salt and water. It is a unidirectional double-displacement reaction, i.e., we can not extract the reactants from the products. It is highly exothermic as the value of delta G is negative.