Question

An electrochemical cell contains a standard hydrogen electrode and a cathode consisting of a metallic chromium electrode, Cr(s), in contact with a 1.00 M chromium solution, Cr3 (aq). The voltage produced by this cell was measured at 25oC. Which statements describe the results of this measurement, assuming the conditions are ideal? The cell voltage with the appropriate sign equals
I. the cell potential.
II. the electromotive force.
III. the standard cell potential.
IV. the standard reduction potential for Cr3+/Cr.

a. I only
b. l and Il
c. I, II and III
d. I, II, II, and IV
e. ll only

Answer 1

Answer:

c. I, II and III

Explanation:

The cell is as follows

Cr / Cr⁺²(1M) // H⁺ ( 1 M ) / H₂

Standard reduction potential of hydrogen cell is zero . Standard reduction potential is negative E for Cr⁺² / Cr(1M) half cell

Cell potential = Ecathode - Eanode

= 0 - ( - E)

= E

E is cell potential and also standard cell potential or emf of the cell .

Standard reduction potential that is for Cr3+/Cr.  is  - E .

Hence statement I , II , III are right . IV th statement is wrong because of sign

Option c is correct.