15 Facts on HF + FeCl3: What, How To Balance & FAQs

FeCl3, or ferric chloride, has a +3 oxidation state. In an aqueous solution, the powerful acid HF completely ionizes. Let us examine the reaction of HF+ FeCl3 in more detail.

FeCl3 appears to be a green-black color, a yellow solid in hexahydrate, and a brown color in solution. HF is an odorless liquid with an acidic composition. In the synthesis of acetic acid, HF functions as a co-catalyst.

In this article, we will discuss important facts about HF + FeCl3 reaction such as the reaction enthalpy, the heat required, the product formed, the type of reaction, the type of intermolecular forces between their compounds, etc.

What is the product of HF and FeCl3?

Ferrous chloride (FeCl2) , Hydrogen Chloride (HCl), and Difluorine gas (F2) are the products that are produced during the reaction of Hydro Fluoric acid (HF) and Ferric chloride (FeCl3).

The chemical equation of this reaction is : HF + FeCl3 → FeCl2 + HCl + F2

What type of reaction is HF + FeCl3?

The reaction between HF and FeCl3 is an oxidation-reduction reaction because of the change in their oxidation numbers.

How to balance HF + FeCl3

The following steps need to be followed while balancing a chemical equation.

  • Given below is an unbalanced chemical reaction of HF and FeCl3,
  • HF + FeCl3 → FeCl2 + HCl + F2
  • Record the moles of each element on the reactant and product sides
Element Reactant Product
H 1 1
F 1 2
Fe 1 1
Cl 3 3
No. of moles of element in reactant and product
  • Now, the number of moles present on each side of the reactant and product must be equal in order to balance the chemical equation. In this case, the number of moles in each element is varied
  • So, in order to make the no. of moles equal on both sides HF present on the reactant side must be multiplied by 2, FeCl3 present on the reactant side must be multiplied by 2, FeCl2 present in the product side must be multiplied by 2 and HCl must be multiplied by 2.
  • Hence, the balanced chemical equation is :
  • 2HF + 2FeCl3 → 2FeCl2 + 2HCl + F2

HF + FeCl3 net ionic equation

The net ionic equation of HF + FeCl3 is :

Fe3+ = 2Fe2++ Cl + F + H+

  • To derive this net ionic eq following steps are followed:
  • Split the strong electrolytes into ions.
  • H+ + F + Fe3+ + 3Cl = 2Fe2+ +2Cl + 2H++ 2Cl + 2F
  • Cancel the spectator ions on both sides and write down the net ionic equation.
  • Fe3+ = 2Fe2++ Cl + F + H+

HF + FeCl3 conjugate pairs

The conjugate acid-base pairs of the reaction are :

  • HF (Conjugate base) = F
  • HCl (Conjugate base) = Cl

HF and FeCl3 intermolecular forces

  • The intermolecular forces exhibited by HF are London – dispersion force and dipole-dipole force.
  • The intermolecular force in the FeCl3 molecule is electrostatic attraction.
  • Dipole-dipole interaction is observed in HCl.

HF + FeCl3 reaction enthalpy

The reaction enthalpy of HF + FeCl3 is 1.31KJ/mol. The standard enthalpy  of the formation of reactants and products is shown below:

Molecules Reaction Enthalpy
(KJ/mol)
HF +28.5
FeCl3 -399.5
HCl -92.3
FeCl2 -341.79
F2 +64.4
Standard enthalpy of formation of molecules.
  • Rection Enthalpy = Enthalpy of product – Enthalpy of reactant
  • Rection Enthalpy = (-92.3-341.79+64.4) – (28.5-399.5) KJ/mol
  • Rection Enthalpy = (-369.69) – (-371) KJ/mol = 1.31 KJ/mol.

Is HF + FeCl3 a buffer solution?

HF + FeCl3 is not a buffer solution as HF is a strong acid, and it does not form a weak acid instead form another strong acid HCl, as a  product.

Is HF + FeCl3 a complete reaction?

 HF + FeCl3 is a complete reaction because no more reaction occurs after the products are formed.

Is HF + FeCl3 an exothermic or endothermic reaction?

HF + FeCl3 is an endothermic reaction as the reaction enthalpy value is positive.

Is HF + FeCl3 a redox reaction?

HF + FeCl3 is a redox reaction because of the following reasons:

  • The oxidation state of Fe changes from (FeCl3)+3 to (FeCl2)+2 (Reduction – FeCl3 acts as an oxidizing agent)
  • The oxidation state of F changes from (HF) -1 to (F2) 0 (Oxidation – HF acts as a reducing agent)

Is HF + FeCl3 a precipitation reaction?

HF + FeCl3 reaction is not a precipitation reaction because no solid product is obtained at the end of the reaction.

Is HF + FeCl3 reversible or irreversible reaction?

HF+ FeCl3 is not a reversible reaction as the product cannot be changed to reactants by any method.

Is HF + FeCl3 displacement reaction?

HF+ FeCl3 is not a displacement reaction because none of the atoms displace each other on the product side.

Conclusion

HF is used in the cativa process and completely ionizes in water. Numerous reactions, including the creation of aromatic compounds, are catalyzed by FeCl3. In metallurgy, it is also used as a leaching agent. A crucial laboratory reagent is HCl.