What kind of reaction is show below (between hydrogen peroxide and magnesium sulfite). a. H2O2(aq) + MgSO3(aq) » MGSO4(aq) + H20 Precipitation gas formation acid-base neutralization redox . Write the total ionic equation for the reaction shown in Question a. Answer: Now convert the total ionic equation in Question b into its net ionic equation.
Solve the problem a, b & C by showing steps properly.
The Correct Answer and Explanation is:
Let’s go through this step by step for the reaction between hydrogen peroxide (H₂O₂) and magnesium sulfite (MgSO₃).
Problem (a): Type of Reaction
Given Reaction: H2O2(aq)+MgSO3(aq)→MgSO4(aq)+H2O(l)\text{H}_2\text{O}_2(aq) + \text{MgSO}_3(aq) \rightarrow \text{MgSO}_4(aq) + \text{H}_2\text{O}(l)
This is a redox reaction.
Here’s why:
- Hydrogen peroxide (H₂O₂) is a known oxidizing and reducing agent.
- Sulfite ion (SO₃²⁻) is oxidized to sulfate ion (SO₄²⁻).
- Hydrogen peroxide is reduced, breaking down into water (H₂O).
So, correct answer: Redox.
Problem (b): Total Ionic Equation
Start by writing all soluble compounds as dissociated ions:
Reactants:
- H₂O₂ is a weak acid-like molecule; stays mostly molecular in solution.
- MgSO₃ dissociates: → Mg²⁺ (aq) + SO₃²⁻ (aq)
Products:
- MgSO₄ is soluble: → Mg²⁺ (aq) + SO₄²⁻ (aq)
- H₂O stays as liquid.
Total Ionic Equation: H2O2(aq)+Mg2+(aq)+SO32−(aq)→Mg2+(aq)+SO42−(aq)+H2O(l)\text{H}_2\text{O}_2(aq) + \text{Mg}^{2+}(aq) + \text{SO}_3^{2-}(aq) \rightarrow \text{Mg}^{2+}(aq) + \text{SO}_4^{2-}(aq) + \text{H}_2\text{O}(l)
Problem (c): Net Ionic Equation
Cancel out the spectator ions. Mg²⁺ appears on both sides.
Net Ionic Equation: H2O2(aq)+SO32−(aq)→SO42−(aq)+H2O(l)\text{H}_2\text{O}_2(aq) + \text{SO}_3^{2-}(aq) \rightarrow \text{SO}_4^{2-}(aq) + \text{H}_2\text{O}(l)
Explanation
This reaction between hydrogen peroxide and magnesium sulfite is a redox reaction. In redox (oxidation-reduction) reactions, one substance loses electrons (is oxidized) and another gains electrons (is reduced). Here, the sulfite ion (SO₃²⁻) is oxidized to sulfate (SO₄²⁻), meaning it gains oxygen or increases its oxidation state. Simultaneously, hydrogen peroxide (H₂O₂) is reduced, breaking down into water, which is a lower oxidation state for oxygen.
Magnesium ions (Mg²⁺) from magnesium sulfite and magnesium sulfate do not participate in the redox process; they are spectator ions. Thus, they cancel out in the net ionic equation.
Hydrogen peroxide acts as a key oxidizing agent in many redox reactions because it contains an O–O bond that readily breaks, allowing oxygen atoms to react. When hydrogen peroxide reacts with the sulfite ion, oxygen is transferred to the sulfite to convert it into sulfate, and H₂O₂ itself turns into H₂O.
The full balanced molecular reaction: H2O2(aq)+MgSO3(aq)→MgSO4(aq)+H2O(l)\text{H}_2\text{O}_2(aq) + \text{MgSO}_3(aq) \rightarrow \text{MgSO}_4(aq) + \text{H}_2\text{O}(l)
Total ionic equation: H2O2(aq)+Mg2+(aq)+SO32−(aq)→Mg2+(aq)+SO42−(aq)+H2O(l)\text{H}_2\text{O}_2(aq) + \text{Mg}^{2+}(aq) + \text{SO}_3^{2-}(aq) \rightarrow \text{Mg}^{2+}(aq) + \text{SO}_4^{2-}(aq) + \text{H}_2\text{O}(l)
Net ionic equation: H2O2(aq)+SO32−(aq)→SO42−(aq)+H2O(l)\text{H}_2\text{O}_2(aq) + \text{SO}_3^{2-}(aq) \rightarrow \text{SO}_4^{2-}(aq) + \text{H}_2\text{O}(l)
This illustrates the role of redox chemistry in transforming compounds and is commonly seen in environmental and biological processes, including disinfection and metabolism.
