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 SideProduct 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.
Comparison of the atoms of the reactant side with the product side
  • 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 SideProduct 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.
Comparison of the atoms of the reactant side with the product side
  • 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 SideProduct 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.
Comparison of the atoms of the reactant side with the product side
  • 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+ + SO42- → 2Na+ + SO42- + 2H2O
  • The 2Na+ and SO42- 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 (SO42-) 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.