Question

What is the EMF of a galvanic cell if the standard reduction potential of the reduction half-reaction is -0.38 volts and the standard reduction potential of the oxidation half-reaction is 0.52 volts?

(a) -0.9 volts

(b) -0.6 volts

(c) 0.9 volts

(d) 0.6 volts

I have been asked this question in quiz.

My doubt stems from Electrochemistry in portion Electrochemistry of Chemistry – Class 12

Answer 1

Right choice is (a) -0.9 volts

The explanation is: Given,

Standard reduction potential of the reduction half reaction = -0.38 volts

Standard reduction potential of the oxidation half reaction = 0.52 volts

Standard EMF of the cell = [Standard reduction potential of the reduction half reaction] – [Standard reduction potential of the oxidation half reaction]

                                             = -0.38 – (0.52)

                                             = -0.9 volts.