11 Facts on HCl + CH4: What, How to Balance & FAQs

CH4 is one of the most potent greenhouse gases, and hydrochloric acid is one of the strongest acids in chemistry. Let us review the following details about how HCl and CH4 react.

Methane is the most basic hydrocarbon in the paraffin series. Methane does not react with hydrochloric acid (HCl), but it can dissociate into its radicals when exposed to UV light, creating a mixture of chloromethane.

This article provides a brief overview of the “HCl + CH4” reaction, including the product, type of reaction, and procedure to balance the reaction.

What is the product of HCl and CH4?

Methane (CH4) and HCl do not interact, but when HCl is exposed to UV, it can become dissociated into its radicals, which can result in the formation of a mixture of chloromethane (CH3Cl).

CH4 + Cl2 → CH3Cl + HCl

What type of reaction is HCl + CH4?

The HCl + CH4 reaction results in a free radical substitution reaction. Chloromethane and hydrogen chloride are created when methane and chlorine react by heating the mixture to a particular temperature. To form methyl chloride, one hydrogen atom is replaced by one chlorine atom in a free radical substitution reaction.

How to balance HCl + CH4?

  • To balance the HCl + CH4 reaction equation, consider the equation after the free radical substitution reaction.
  • Count the number of C, Cl, and H atoms on each side of the chemical equation.
  • Simply change the coefficients, or the numbers preceding the atoms or compounds, to balance the equation.
  • For the equation to be balanced, the number of each atom on both sides of the equation must be the same.
  • After adjusting the coefficients, the equation ends up looking like this,

CH4 + 2Cl2 → CH2Cl2 + 2HCl

HCl and CH4 intermolecular forces

  • In HCl + CH4 the main intermolecular force for HCl (hydrogen chloride) is the dipole-dipole force, and for CH4 (methane) is the London dispersion force.
  • HCl is a molecular compound; there are no ions present in it.
  • Since CH4 is a symmetrical molecule and the atoms have little variation in electronegativity, it is regarded as non-polar.

HCl + CH4 reaction enthalpy

The enthalpy change for the reaction HCl + CH4 is △H= -115 kJ mol−1 . △H = [Bond energy for bond dissociation] + [Bond energy for bond formation]. The information in the table below demonstrates how bond strengths vary across the periodic table.

BondBond dissociation energy (kJ/mol)
Bond and their dissociation energy

Is HCl + CH4 a buffer solution?

HCl + CH4 would not result in a buffer solution because HCl is a strong acid and not a weak acid.

Is HCl + CH4 a complete reaction?

The HCl+CH4 reaction produces a complete reaction that results in a free radical substitution reaction, which takes place when one atom or molecule from a compound is exchanged for another atom or molecule.

CH4 + Cl2 → CH2Cl2 + HCl

Is HCl + CH4 an exothermic or endothermic reaction?

HCl + CH4 is an exothermic reaction. Here, -115 kJ/mol is the enthalpy change for the reaction, and that is a negative value, indicating it produces energy.

Is HCl+ CH4 a redox reaction?

HCl+ CH4 is a redox reaction. On the reactants’ side, (in CH4) the oxidation numbers of carbon are -4, hydrogen is +1, and chlorine is in the Free State. While, on the products side, (in CH2Cl2) Carbon has an oxidation number of 0 and chlorine has an oxidation state of (-1).

Is HCl + CH4 a precipitation reaction?

The above reaction is not a precipitate reaction as hydrochloric acid does not precipitate with aqueous chlorine ions.

Is HCl + CH4 displacement reaction?

The reaction HCl + CH4 is a displacement reaction. Chlorine (Cl2) displaces a proton from methane (CH4) to form hydrochloric acid (HCl) in the given reaction. During the reaction, methyl chloride (CH3Cl) is also formed.


Methane does not react with hydrochloric acid (HCl), but when exposed to UV light, it can dissociate into its radicals, resulting in a chloromethane mixture. The HCl+CH4 reaction is a complete reaction involving free radical substitution.

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