Question

Consider the following standard reduction potentials:

02(8) +4H* (aq) + 4€™ →2 H20 (0)
Ni2+ (aq) +2 e" → Ni (s)
Fe2+ (aq) + 2 e™ → Fe (s)
Zn?+ (aq) +2 e^ →Zn (s)
Which process will occur to act as a sacrificial anode for iron?
• 2H20 () to 02 (s)
• 02 (s) to 2 H20 (I)
• Zn (s) to Zn?* (aq)
Ni (s) to Ni?+ (aq)
Ni2* (aq) to Ni (s)
• Zn?* (aq) to Zn (s)
+1.23V
-0.28V
-0.45 V
-0.77V

Answer 1

Zinc (Zn) will act as a sacrificial anode for iron, as it has a more negative standard reduction potential than iron, leading to its oxidation and prevention of corrosion in iron.

Step-by-step explanation:

The process that will occur to act as a sacrificial anode for iron is the oxidation of Zn to Zn2+ (aq). According to the provided standard reduction potentials, the reaction at the anode for zinc's oxidation is:

Zn (s) → Zn2+ (aq) + 2e−

For sacrificial anode protection, the anode must have a more negative potential than the metal it is protecting. In this case, iron has a standard reduction potential of -0.45 V while zinc has a standard reduction potential of -0.77 V, indicating that zinc will act as the sacrificial anode for iron. When zinc corrodes, it forms Zn2+ ions, while iron remains protected from corrosion.