Question
Which of the following net cell reactions occurs in a galvanic cell containing cadmium electrode and standard hydrogen electrode? E ^ _ ( Cd ^ 2+ _ (aq) | Cd _ (s) ) = -0.403\ V .
MHT CET
Chemistry
Electrochemistry
2026
MHT CET 2026 (18 April Shift 1)
MHT CET Chemistry Question (2026) — Solution
Options
- A. H _ 2(g) + Cd ^ 2+ _ (aq) 2 H ^+_ (aq) + Cd _ (s)
- B. Cd _ (s) + 2 H ^+_ (aq) Cd ^ 2+ _ (aq) + H _ 2(g)
- C. 2 H _ 2(g) + Cd ^ 2+ _ (aq) 4 H ^+_ (aq) + Cd _ (s)
- D. 2 Cd _ (s) + 2 H ^+_ (aq) 2 Cd ^ 2+ _ (aq) + H _ 2(g)
Answer
B. Cd _ (s) + 2 H ^+_ (aq) Cd ^ 2+ _ (aq) + H _ 2(g)
Step-by-step solution
Given E^ _ Cd ^ 2+ | Cd = -0.403\ V and E^ _ H ^+| H _2 = 0.00\ V . Since the standard reduction potential of cadmium is lower than that of hydrogen, cadmium has a higher tendency to get oxidized. Therefore, cadmium will act as the anode (oxidation) and the standard hydrogen electrode will act as the cathode (reduction). At anode: Cd _ (s) Cd ^ 2+ _ (aq) + 2 e ^- At cathode: 2 H ^+_ (aq) + 2 e ^- H _ 2(g) Adding the two half-cell reactions, the net cell reaction is: Cd _ (s) + 2 H ^+_ (aq) Cd ^ 2+ _ (aq) + H _ 2(g) Answer: Cd _ (s) + 2 H ^+_ (aq) Cd ^ 2+ _ (aq) + H _ 2(g)
Related: Chemistry — Electrochemistry · All PYQ Banks