15 Facts on HCl + FeCO3: What, How To Balance & FAQs

HCl is a strong acid while FeCO₃ is a base. Let us explore the reaction between HCl and FeCO₃ in detail.

Hydrochloric acid (HCl) is a colorless, transparent liquid. It is a strong acid with a pungent odor. FeCO₃ is iron(ll) Carbonate. It exists as white powder or crystals. It is a base.

Let us discuss the products formed in this reaction, type of reaction, balancing the reaction, net ionic equation, titration, conjugate pairs, reaction enthalpy and some more important in this article.

What is the product of HCl and FeCO₃?

The product formed in the reaction of HCl and FeCO₃ are ferrous chloride (FeCl₂), carbon dioxide (CO₂) and water (H₂O) are as below.

2HCl + FeCO₃ –> FeCl₂ + CO₂ + H₂O

What type of reaction is HCl + FeCO₃?

HCl + FeCO₃ is a acid-base reaction or a neutralization reaction where acid and base react to form salt and water. It is also displacement reaction where there is an exchange of ions between the reacting species.

How to balance HCl + FeCO₃?

To balance the chemical reaction, the following steps need to be followed-

Step 1: Write the skeletal chemical equation

Write the unbalanced chemical equation with reactants on the right side, left pointing arrow and products on the left side of the reaction.

HCl + FeCO₃ –>FeCl₂ + CO₂ + H₂O

Step 2: Count the number of moles for each element

Count the number of moles for each element on the reactant and the product side in the chemical Equation.

Elements	No. of moles on Reactant side	No. of moles on Product side
H	1	2
Cl	1	2
Fe	1	1
C	1	1
O	3	3

             

• As we can see from the above table that H and Cl are the only unbalanced atoms. Adding stoichiometric coefficient before the appropriate molecule will balance H and Cl.
• In this reaction HCl molecule contains both H and Cl atom. Multiply HCl by 2 will balance the whole chemical equation.

Step 3: Write the balanced chemical equation

2HCl + FeCO₃ –>FeCl₂ + CO₂ + H₂O

HCl and FeCO₃ titration

To determine the % composition of FeCO₃ in a given sample, we need to titrate it with HCl solution. The titration between HCl and FeCO₃ can be carried out as follows-

Apparatus

Burette stand, Graduated Burette, volumetric flask, pipette, beakers

Chemicals Needed

FeCO₃ (whose concentration needs to be analysed), HCl (concentration is known), Indicator

Procedure

• First the solution of HCl needs to be standardized. To standardize the HCl solution, titrate the solution of HCl with a primary standard like Na₂CO₃.
• Write the balanced neutralization reaction of HCl with Na₂CO_3. Take measured amount of Na₂CO₃ dissolve it in some water. Add a colorimetric indicator to it.
• HCl solution was added to Na₂CO₃ to reach the equivalence point.
• Now, the amount of FeCO₃ can be determined by titrating it with the standardized HCl solution.
• The amount of HCl required to neutralise the FeCO_3, will give the amount of FeCO₃ in the given sample.

HCl + FeCO₃ net ionic equation

Complete ionic equation can be written as follows –

2H⁺_(aq) + 2Cl^–_(aq) + FeCO_3(s) = 2H⁺_(aq) + CO₃^2- _(aq) + Fe²⁺ _(aq) + 2Cl^– _(aq)

• Now, to write net ionic equation we will remove the spectator ions from the equation. Net ionic equation will consist of the species which are taking part in the reaction.
• The net ionic equation is as follows-

FeCO_3(s) = Fe²⁺ _(aq) + CO₃^2- _(aq)

HCl and FeCO₃ conjugate pairs

HCl being a strong acid donates a proton(H⁺) and forms Cl^– ion. CO₃^2- being a weak base accepts the proton to form its conjugate acid HCO₃^–. The conjugate pairs of HCl + FeCO₃ is as follows-

 

        

HCl and FeCO₃ intermolecular forces

The intermolecular forces present in HCl and FeCO₃ are as under –

• The intermolecular forces present in HCl are stronger Dipole-dipole forces and London dispersion forces. The dipole -dipole forces arise due to the as Cl is more electronegative than H atom.
• FeCO₃ is an ionic compound so the intermolecular force present is electrostatic force. Thus, there is a strong force of attraction between Fe²⁺and CO₃^2-.

HCl and FeCO₃ reaction enthalpy

The reaction enthalpy for the reaction of HCl and FeCO₃ is 81.87 kJ/mol at 298 K. The reaction enthalpy can be calculated by using the formula –

 ∆H⁰_f = ∆H⁰_{f (products)} – ∆H⁰_{f (reactants)}

Compounds	∆H0f (kJ/mol)
HCl	-334.32
FeCO3	-738.15
FeCl2	-311.34
CO2	-393.5
H2O	-285.76

Is HCl and FeCO₃ a buffer solution?

HCl and FeCO₃ is not a buffer solution. A buffer solution is a water-based solution of a weak acid and its conjugate base or a weak base and its conjugate acid. In this reaction, HCl is a strong acid while FeCO₃ is a base. So HCl and FeCO₃ is not a buffer.

Is HCl and FeCO₃ a complete reaction?

HCl and FeCO₃ is a complete reaction because it products formed do not show the formation of products.

Is HCl and FeCO₃ an exothermic or endothermic reaction?

The reaction between HCl and FeCO₃ is an endothermic reaction because reaction enthalpy of this reaction is positive. Positive value of enthalpy means the reaction is non-spontaneous.

Is HCl and FeCO₃ a redox reaction?

HCl and FeCO₃ does not involve electron transfer so it is not a redox reaction. It is a acid-base reaction.

Is HCl and FeCO₃ a precipitation reaction?

HCl and FeCO₃ is not a precipitation reaction because the products formed are not insoluble in water. FeCl₂ is soluble in water. CO₂ is a gas which releases from the reaction medium.

Is HCl and FeCO₃ reversible or irreversible reaction?

HCl and FeCO₃ reaction is irreversible because the gas (CO₂) formed in the reaction increases the entropy of the reaction. It is not possible to collect the gas molecules and turn them back into reactants.

Is HCl and FeCO₃ displacement reaction?

HCl and FeCO₃ is a double displacement reaction because in this reaction there is a exchange of ions CO₃^2- and Cl^– between the reacting species and there is also evolution of CO₂ gas.

Conclusion:

HCl and FeCO₃ is an acid-base (neutralization) reaction. It is an endothermic reaction. The reaction enthalpy for the reaction is found to be 81.87 kJ/mol.