Question

The information below describes a redox reaction.

3 equations: First: upper C r superscript 3 plus (a q) plus 2 upper C l superscript minus (a q) right arrow upper C r (s) plus upper C l subscript 2 (g). Second: 2 upper C l superscript minus (a q) right arrow upper C l subscript 2 (g) plus 2 e superscript minus. Third: upper Cr superscript 3 plus (a q) plus 3 e superscript minus right arrow upper C r (s).

What is the final, balanced equation for this reaction?
2 upper C r superscript 3 plus (a q) plus 6 upper C l superscript minus (a q) right arrow 2 upper C r (s) plus 3 upper C l subscript 2 (g).
2 upper C r superscript 3 plus (a q) plus 2 upper C l superscript minus (a q) plus 6 e superscript minus right arrow upper C l subscript 2 (g) plus 2 upper C r (s).
Upper C r superscript 3 plus (a q) plus 6 upper C l superscript minus (a q) plus 3 e superscript minus right arrow 2 upper r (s) plus 3 upper C l subscript 2 (g).
Upper C r superscript 3 plus (a q) plus 2 upper C l superscript minus (a q) right arrow upper C r (s) plus upper C l subscript 2 (g).

Answer 1

2 Cr3+ (aq) + 6 Cl− (aq) → 2 Cr (s) + 3 Cl2 (g)

(Obtain by multiplying the Cl− half-reaction by 3 and the Cr3+ half-reaction by 2 so the 6 e− cancel.)