15 Facts on HCl + Fe2(SO4)3: What, How To Balance & FAQs

The solution of hydrochloric acid has a harsh, repulsive odour and is colourless and watery. Let us see how HCl and Fe2(SO4)3 react chemically.

Hydrogen chloride is dissolved in water and forms a mist when merged with water after sinking. The chemical compound known as iron(III) sulphate (transition metal sulphate) has the formula Fe2(SO4)3 commonly referred to as ferric sulphate. Diiron trisulfate reacts with acid and bases at standard temperature.

Let us discuss the HCl + Fe2(SO4)3 reaction, the formation of the product, balancing, the titration in detail.

What is the product of HCl and Fe2(SO4)3?

When iron sulphate(Fe2(SO4)3) reacts with hydrochloric acid(HCl) that produces a prominent byproduct such as sulfuric acid(H2SO4) and ferric chloride(FeCl3).

HCl + Fe2(SO4)3 →  H2SO4 + FeCl3

What type of reaction is HCl + Fe2(SO4)3?

HCl + Fe2(SO4)3 is a displacement reaction, irreversible and exothermic reaction.

How to balance HCl + Fe2(SO4)3?

Step 1: Finding the number of atoms in reactants and products

This is the fundamental step to finding the number of participating atoms in reactants and products. The general equation is displaying that in reactants 1H, 1Cl, 2Fe, 3S, and 12O. In product 2H, 1S, 4O, 1Fe, 3Cl. 

HCl + Fe2(SO4)3 = H2SO4 + FeCl3

Step 2: Arranging the similarity between the number of molecules in reactants and products

The reaction between HCl and Fe2(SO4)3 is balanced by arranging the same number of atoms or molecules. By multiplying 6 with HCl and 3 with Fe2(SO4)3 and 2 with FeCl3 the first attempt at balancing has been carried out

6HCl + Fe2(SO4)3 = 3H2SO4 + 2FeCl3

Step 3: Find the coefficient of the equation

The Gauss elimination method calculates all the variables and coefficients. The resulting coefficient is 6:1:3:2 which means.

Step 4: Write the Balanced Chemical Equation

Finally, all the elements present in the chemical equation are balanced and the reaction is as follows: 6HCl + Fe2(SO4)3 →  3H2SO4 + 2FeCl3

HCl + Fe2(SO4)3 titration

The titration reaction of hydrochloric acid vs iron sulphate is mentioned below: 

6HCl + Fe2(SO4)3 →  3H2SO4 + 2FeCl3

Apparatus used

Pipette, burette clamp, rubber tube with a syringe attached to the pipette, grease stand with a pencil and a beaker with different sizes (250 ml-1, 100 ml-3) and 250 ml flask.

Titrant and titer

The molecule will be examined as iron sulphate after the titer was taken in a conical flask, and the titration will employ hydrochloric acid as the titrant filled in the burette.


Phenolphthalein or methyl orange, which is green in basic pH and violates acidic pH used as an indicator.


  1. Prepare a batch of 250 mL of hydrochloric acid solution 
  2. The solution should be diluted with 100 mL of distilled water.
  3. Add a few drops of the methyl orange or phenolphthalein solution to the mixture.
  4. Once the iron sulphate solution is titrated, the colour should initially change.
  5. Repeat the procedure 3–4 times to get a reading.

HCl + Fe2(SO4)3 net ionic equation

The Net ionic equation is written using the following steps:

Step 1: Write the equation for the molecules in a balanced form:

6HCl + Fe2(SO4)3 →  3H2SO4 + 2FeCl3

Step 2: Give each substance a state (solid (s), liquid (l), gas (g), or aqueous (aq)):

6HCl + Fe2(SO4)3 →  3H2SO4 + 2FeCl3

Step 3: Divide each ion into its ionic parts:

H2SO4 → 2H+ + 3(SO4)2-

FeCl3 → 2Fe3+ + 6Cl

Fe2(SO4)3 Fe2(SO4)3 (because it is in solid form)

HCl → H++ Cl

Step 4: Write the ionic equation:

2Fe3+(aq) + 3SO42-(aq) + 6H+(aq) + 6Cl(aq) → 6H+(aq) + 3SO42-(aq) + 2Fe3+(aq) + 6Cl(aq)

Step 5: Eliminates the spectator ligand:

Both H+ and Cl behave as spectator ions and can be removed from both sides of the equation.

Step 6: The net ionic equation: 

Fe2(SO4)3→ 3SO42-(aq) + 2Fe3+(aq)

HCl + Fe2(SO4)3 conjugate pairs

  • The conjugate base of hydrochloric acid and the appropriate conjugate acid of the salt make up the conjugate pair in the reaction between iron sulphate and hydrochloric acid. 
  • When a Bronsted base accepts a proton, a conjugate acid is created, and when a Bronsted acid donates a proton, a conjugate base is created.
  • Base Conjugate pairs = HCl
  • Conjugate acid pair = H2SO4

HCl and Fe2(SO4)3 intermolecular forces

  • The intermolecular force between HCl and Fe2(SO4)3 is an intermolecular force of attraction or dipole-dipole interaction, even though hydrochloric acid (HCl) possesses a London dispersion force, which is greater. 
  • The polar property of HCl causes it to interact with other polar molecules via dipoles, Hδ+−Clδ−
  • If there is no dipole-dipole interaction, HCl cannot dissolve in water.

HCl + Fe2(SO4)3 reaction enthalpy

  • Iron sulphate and hydrochloric acid typically react with a negative standard reaction enthalpy.
  • Mathematically,  ΔtH is equal to the total of the enthalpies of the reactants and the sum of the enthalpies of the product.
  • δH = Hproducts-Hreactans= -ve

ΔtH = (-928.4 kJ/mol) + (-167.2 kJ/mol) – (-909.3 kJ/mol) + (-399.5kJ/mol)

ΔtH (kJ/mol)= −(2585.2) kJ/mol

Is HCl + Fe2(SO4)3 a buffer solution?

The reaction of hydrochloric acid with iron sulphate is complete and irreversible, so the buffer cannot be produced in an aqueous solution. Weak bases or acids and their salts are combined to form buffer solutions.

Is HCl + Fe2(SO4)3 a complete reaction?

The HCl + Fe2(SO4)3 reaction can be considered complete because the reaction is irreversible. All of the reactant molecules will entirely transform into product molecules as seen in the reaction below:

HCl + Fe2(SO4)3 →  H2SO4 + FeCl3 

Is HCl + Fe2(SO4)3 an exothermic or endothermic reaction?

Fe2(SO4)3 and HCl react exothermically, which means that heat is released in the form of energy and more stable product molecules are produced. Because less stable reactant molecules engage in the irreversible process, displacement reactions are typically exothermic reactions.

Is HCl + Fe2(SO4)3 a redox reaction?

HCl + Fe2(SO4)3 is not a redox reaction when HCl + Fe2(SO4)3 →  H2SO4 + FeCl3. The oxidation states of the components remained constant throughout the reaction.

Is HCl + Fe2(SO4)3 a precipitation reaction?

The HCl + Fe2(SO4)3 reaction is not a precipitate reaction. Because Iron(III) chloride is a soluble salt, this is not a precipitate reaction. By the solubility principle, metal chlorides are soluble except for silver and lead ions. 

Is HCl + Fe2(SO4)3 reversible or irreversible reaction?

The reaction between iron(II) sulphate and hydrochloric acid described above is irreversible because the reactant molecules undergo a displacement reaction and the process cannot go in the other direction. As opposed to weak acid and base reactions, displacement reactions tend not to be reversible.

Is HCl + Fe2(SO4)3 displacement reaction?

The reaction between iron(II) sulphate and hydrochloric acid is referred to as a displacement reaction because the two reactant molecules transfer ions during their interaction to produce two entirely different compounds.


The reaction of hydrochloric acid with iron sulphate is complete and irreversible, so the buffer cannot be produced in an aqueous solution. Fe2(SO4)3 and HCl react exothermically, which means that heat is released in the form of energy and more stable product molecules are produced.

Monika Saini

Hi....I am Monika. I have done Masters in Chemistry. I am a Subject Matter Expert in Chemistry. I would say that I am a very passionate writer. The main goal of my writing is to present new perspectives. I want to discover new things that I can apply to my surroundings. Let's connect through LinkedIn-https://www.linkedin.com/in/monadbscr171291

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