Question

In the reaction 2H2O (l) + 2Cl– (aq) → H2 (g) + Cl2 (g) + 2OH– (aq), how many electrons are transferred?

A. 0
B. 1
C. 2
D. 3
E. None of the Above (This is not a redox reaction.)

Answer 1

C. 2

2H_2O + 2e^(-) → H_2 + 2OH^(-)

2Cl^(-) → Cl_2 + 2e^(-)

2H_2O +Cl^(-) + 2e^(-) → H_2 + Cl_2 + 2OH^(-) + 2e^(-)

2H_2O +2Cl^(-) → H_2 + Cl_2 + 2OH^(-)

This is a redox reaction in which two chloride ions transfer two electrons to two molecules of water.