Answer:
The value of n is 6
Step-by-step explanation:
The half-reactions of the problem are:
Cr(s) → Cr³⁺ + 3e⁻
Pb²⁺ + 2e⁻→ Pb(s)
To balance the electrons we must multiply the half-reactions as follows:
2 * (Cr(s) → Cr³⁺ + 3e⁻)
3 * (Pb²⁺ + 2e⁻→ Pb(s))
2Cr(s) → 2Cr³⁺ + 6e⁻
3Pb²⁺ + 6e⁻→ 3Pb(s)
In Nernst equation, the value of n are the electrons used to balance the reaction, as in this problem, the electrons are 6:
The value of n is 6