15 Facts on HCl + Na2CO3: What, How To Balance & FAQs

Hydrochloric acid is a strong reactive acid that tends to interact with bases such as Sodium carbonate. Let us explore their reaction in depth.

HCl + Na2CO3 is a fundamental reaction between a strong acid and weak base. Hydrochloric acid is usually formed from an aqueous solution of hydrogen chloride gas. Sodium carbonate (Na2CO3), also known as washing soda, is an inorganic chemical that is miscible in water and appears as a white, odorless crystalline solid.

This article shall go through various characteristics about this reaction such as the products, the reaction type, titration, enthalpy of the reaction, etc.

What is the product of HCl + Na2CO3

Sodium chloride is formed along with water and carbon dioxide, when HCl is reacted with Na2CO3.

2HCl (aq) + Na2CO3 (aq) —> 2NaCl (aq) + H2O (l) + CO2 (g)

What type of reaction is HCl + Na2CO3

HCl + Na2CO3 is an acid-base reaction, also referred to as neutralization reaction, wherein HCl is the strong acid, and Na2CO3 is the weak base.

How to balance HCl + Na2CO3

The unbalance equation is: HCl + Na2CO3 = NaCl + H2O + CO2

Following steps are applied to equate the above-mentioned reaction:

  • For the reaction to be balanced, the number of atoms of each element present on both the reactant and product sides must be equal.
AtomsReactant SideProduct Side
Sodium21
Chlorine11
Carbon11
Hydrogen12
Oxygen33
Table representing count of atoms from the unbalanced equation
  • Stoichiometric coefficients are added to the unbalanced atoms on the reactant and product sides as needed.
  • To balance the sodium atom, NaCl is multiplied with coefficient 2.
  • The carbon and oxygen atoms are already balanced on both sides of the reaction.
  • Finally, the hydrogen atom is balanced by multiplying HCl with coefficient 2.
  • Hence, The balanced chemical equation is:
  • 2HCl + Na2CO3 = 2NaCl + H2O + CO2

HCl + Na2CO3 Titration

HCl + Na2CO3 titration falls under the category of strong acid weak base titration and it can be carried out in the following manner.

Apparatus and Chemicals Required

50 ml Burette, Pipette, 250 ml Conical flask, Measuring flask, Burette stand, Beaker, Funnel, Distilled water, Hydrochloric acid, Sodium carbonate

Indicator

This titration is carried out using a methyl orange indicator to mark the endpoint with a physical transition in the solution.

Procedure

  • A standard solution of Na2CO3 is prepared by dissolving a few grams of it in distilled water.
  • The burette is filled with standardized Na2CO3 solution after washing and rinsing it.
  • HCl solution is transferred into a clean, rinsed titration flask using a pipette, and 2 drops of methyl orange is added to it. 
  • The sodium carbonate solution is added to the titration flask in a drop-wise manner. The flask is vigorously shaken until the color of the solution changes to light pink. This colour change indicates the endpoint of the reaction.
  • The final reading is then noted, and the amount of Na2CO3 solution used to neutralize the HCl solution is determined.
  • The preceding steps are repeated until three concordant readings are obtained.
  • The volume of the required chemical is calculated using the formula M1V1 = M2V2

HCl + Na2CO3 Net Ionic Equation

The net ionic equation of HCl + Na2CO3 is: CO32- (aq) + 2H+ (aq) = H2O (l) + CO2 (g)

Following are the steps to derive the net ionic equation:

  • Firstly, the complete balanced equation is written along with their physical states.
  • 2HCl (aq) + Na2CO3 (aq) = 2NaCl (aq) + H2O (l) + CO2 (g)
  • Now, the atoms are split into ions. Thus, the balanced net ionic equation between HCl and Na2CO3 after eliminating the spectator ions is as follows:
  • CO32- (aq) + 2H+ (aq) = H2O (l) + CO2 (g)

HCl + Na2CO3 Conjugate Pairs

  • The conjugate base of HCl is Cl since HCl donates a proton to form Clion.
  • The conjugate acid of CO32- ion is HCO3 since Na2CO3 dissociates in water to form Na+ and CO32- ions.

HCl + Na2CO3 Intermolecular Forces

HCl + Na2CO3 Reaction Enthalpy

The reaction enthalpy of HCl + Na2CO3 is -2.2 kJ/mol.

CompoundsNumber of molesBond Enthalpy, ΔH⁰f (kJ/mol)
HCl2-167.15
Na2CO31-1157.3
NaCl2-407.25
H2O1-285.8
CO21-393.5
Bond enthalpy values
  • The enthalpy of reaction is calculated using the formula: ΔH⁰f (reaction) = ΣΔH⁰f (products) ΣΔH⁰f (reactants)
  • Enthalpy change = [2*(-407.25) + 1*(-285.8) + 1*(-393.5)] – [2*(-167.15) + 1*(-1157.3)] = -2.2 kJ/mol

Is HCl + Na2CO3 a Buffer Solution

HCl + Na2CO3 reaction does not form a buffer solution, because of the presence of a strong acid which simply gets neutralized with the base, resulting in the formation of salt.

Is HCl + Na2CO3 a Complete Reaction

HCl + Na2CO3 is a complete reaction as the reacting compounds are complete and totally consumed at equilibrium, forming a stable salt with bubbles of CO2 gas being evolved out. Thereby, no further reaction is possible.

Is HCl + Na2CO3 an Exothermic or Endothermic Reaction

HCl + Na2CO3 is an exothermic reaction as the change in enthalpy for this reaction is negative, and the energy is released in the form of heat.

Is HCl + Na2CO3 a Redox Reaction

HCl + Na2CO3 is not a redox reaction since no change in the oxidation number of each of the reacting atoms is observed on both the reactant and product sides.

Is HCl + Na2CO3 a Precipitation Reaction

HCl + Na2CO3 is not a precipitation reaction as the NaCl produced is a salt that easily dissolves in water rather than forming a precipitate.

Is HCl + Na2CO3 a Reversible or Irreversible Reaction

HCl + Na2CO3 is an irreversible reaction because the products obtained cannot be reversed to generate the reactants. The produced Carbon dioxide freely leaves the solution, strongly pushing the equilibrium forward.

Is HCl + Na2CO3 Displacement Reaction

HCl + Na2CO3 is a double displacement reaction because it involves the exchange of cationic and anionic parts of the molecule.

Displacement 1
Double displacement mechanism

Conclusion

The reaction of Na2CO3 with HCl is a well-known spontaneous, effervescence neutralization process that results in the formation of a salt, NaCl. Salt formation is significantly used in manufacturing various chemicals in a diverse range of industries, either directly or indirectly. It also exhibits medical applications.