13 Facts on HI + MgSO3: What, How To Balance & FAQs

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MgSO3 is an anhydrous salt of Magnesium. Let us go into detail about what will happen when it will react with strong acid HI.

Magnesium Sulfite (MgSO3) readily absorbs water from the air which means that it is hygroscopic in nature. Hydrogen Iodide (HI) belongs to the category of strong acids. Both are strong electrolytes and dissociate into ions easily.

In this article, we will discuss important facts about HI + MgSO3 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 HI and MgSO3?

Magnesium Iodide (MgI2) and Sulfurous acid (H2SO3) are yielded as products when Hydrogen Iodide HI reacts with Magnesium Sulfite MgSO3.

The chemical equation for the reaction is,

MgSO3 + HI → MgI2 + H2SO3

What type of reaction is HI + MgSO3?

HI + MgSO3 is a Double-Displacement reaction because the Iodide ion is transferred from HI to MgI2 and the Hydrogen ion is transferred from HI to H2SO3.

How to balance HI + MgSO3

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

  • Given below is an unbalanced chemical reaction of HI and MgSO3,
  • MgSO3 + HI → MgI2 + H2SO3
  • Record the moles of each element on the reactant and product sides.
ElementReactantProduct
Mg11
S11
O33
H12
I12
No. of moles of the 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.
  • Hence, in order to balance the moles of elements on both sides Hydrogen Iodide present on the reactant side must be multiplied by 2.
  • So, the balanced chemical equation is :

MgSO3 + 2HI → MgI2 + H2SO3

HI + MgSO3 titration

The titration of HI and MgSO3 is categorized as acid-base titration. HI is a strong acid and MgSO3 is a strong base.

Apparatus:

Burette, conical flask, burette stand, beaker, funnel, pipette.

Indicator Used:

Phenolphthalein is used as an indicator here.

Procedure:

  • Wash, rinse and fill the burette with a standardized solution of MgSO3 and fit it in a burette stand.
  • Pipette out 10mL of HI in a conical flask and add 2-3 drops of phenolphthalein indicator in it.
  • Start adding MgSO3 solution in the conical flask in a dropwise manner with constant swirling.
  • The colour of the HI + MgSO3 solution in the conical flask will change to light pink on reaching the endpoint.
  • Repeat these steps to get concurrent readings.
  • The concentration of HI is calculated using the formula S1V1 = S2V2.

HI + MgSO3 net ionic equation

The net ionic equation of HI + MgSO3 is :

H+ + I– + Mg2+ + SO32- = Mg2+ + 2I– + 2H+ + SO32-

  • To derive this net ionic eq following steps are followed:
  • Split the strong electrolytes into ions.
  • H+ + I– + Mg2+ + SO32- = Mg2+ + 2I– + 2H+ + SO32-
  • Cancel the spectator ions on both sides and write down the net ionic equation.

HI + MgSO3 conjugate pairs

The conjugate acid-base pairs of HI+MgSO3

  • HI (Conjugate base) = I–
  • H2SO3 (Conjugate base) = HSO3–

HI and MgSO3 intermolecular forces

The intermolecular forces present are:

  • Strong ionic interaction, dipole–dipole interaction, and hydrogen bonding exist in HI molecules because HI is a highly polar molecule due to the high electronegativity difference between hydrogen and iodine atoms.
  • I2 molecules show strong London dispersion forces between their atoms because of their nonpolar and covalent nature.  

Is HI + MgSO3 a buffer solution?

HI + MgSO3 is not a buffer solution because the HI present here is a strong acid and there must be a weak acid present for a buffer solution.

Is HI + MgSO3 a complete reaction?

HI + MgSO3 is a complete reaction since all of the reactant’s moles are completely converted and consumed by the product at equilibrium.

Is HI + MgSO3 an exothermic or endothermic reaction?

The reaction HI + MgSO3 is an endothermic reaction because the net change of enthalpy is positive (415.48 kJ/mol).

Is HI + MgSO3 a redox reaction?

HI + MgSO3 is not a redox reaction because there is no change in the oxidation state of any element either in the reactant or product side.

Is HI + MgSO3 a precipitation reaction?

HI + MgSO3 reaction is not a precipitation reaction because no solid product is obtained at the end of the reaction.

Is HI + MgSO3 reversible or irreversible reaction?

HI+ MgSO3 is irreversible because the products no longer undergo backward reactions to form reactants under the same conditions.

Is HI + MgSO3 displacement reaction?

HI and MgSO3 is a double displacement reaction because the Iodide ion is transferred from HI to MgI2 and the Hydrogen ion is transferred from HI to H2SO3.

Conclusion

Magnesium Iodide which is the product of this reaction is stable only under high temperatures but when there is a normal temperature it decomposes into the air. It also has some commercial uses and is also used for many organic synthesis of compounds.