Final answer:
In the reaction 2 Cr(s) + 3 Pb₂⁺ (aq) → 3 Pb(s) + 2 Cr₃⁺(aq), the value of n in the Nernst equation is 6, as this is the number of electrons transferred during the balanced redox reaction.
Step-by-step explanation:
The value of n in the Nernst equation represents the number of moles of electrons transferred in a balanced redox reaction. For the reaction 2 Cr(s) + 3 Pb₂⁺ (aq) → 3 Pb(s) + 2 Cr₃⁺(aq), we need to balance the electron transfer.
Each Cr atom loses 3 electrons to become Cr₃⁺ (for a total of 6 electrons since there are 2 Cr atoms), and each Pb₂⁺ gains 2 electrons to become Pb (for a total of 6 electrons over 3 Pb₂⁺ ions). Therefore, n is equal to 6 because that is the total number of electrons transferred during the reaction.