Question

The information below describes a redox reaction.

( Cr³⁺ (aq) + 2Cl⁻ (aq) → Cr(s) + Cl₂(g) )
( 2Cl⁻ → Cl₂(g) + 2e )
( Cr³⁺ (aq) + 3e → Cr(s) )
What is the final, balanced equation for this reaction?
A) ( 2Cr³⁺ (aq) + 6Cl⁻ (aq) → 2Cr(s) + 3Cl₂(g) )
B) ( 2Cr³⁺ (aq) + 2Cl⁻ (aq) + 6e → Cl₂(g) + 2Cr(s) )
C) ( Cr³⁺ (aq) + 6Cl⁻ (aq) + 3e → 2Cr(s) + 3Cl₂(g) )
D) ( Cr³⁺ (aq) + 2O₂²⁻ (aq) → Cr(s) + Cl₂(g) )

Answer 1

The final, balanced equation for the redox reaction is option C) (Cr³⁺ (aq) + 6Cl⁻ (aq) + 3e → 2Cr(s) + 3Cl₂(g)).

Step-by-step explanation:

The final, balanced equation for the redox reaction is option C) (Cr³⁺ (aq) + 6Cl⁻ (aq) + 3e → 2Cr(s) + 3Cl₂(g)).

The equation is balanced by atoms and by charge. The oxidation half-reaction is 2Cl⁻ → Cl₂(g) + 2e and the reduction half-reaction is Cr³⁺ (aq) + 3e → Cr(s). By multiplying the oxidation by 2 and the reduction by 3, the number of electrons lost and gained are equal.