Question

In part B of Lab 11, you measured the voltage of several galvanic cells. Assemble a battery, represented by the diagram below with the cathode in compartment A, with Zn2+/Zn and Fe2+/Fe couples in which the voltage reads positive. (Use the Standard Reduction Potentials Table. Use the lowest possible coefficients. Omit states-of-matter from your answer.)

In part B of Lab 11, you measured the voltage of several galvanic cells. Assemble a battery, represented by the diagram below with the cathode in compartment A, with Zn2+/Zn and Fe2+/Fe couples in which the voltage reads positive. (Use the Standard Reduction Potentials Table. Use the lowest possible coefficients. Omit states-of-matter from your answer.) What half-reaction occurs in compartment A?(b) What half-reaction occurs in compartment B?(c) Write the net redox reaction.(d) What is the cell potential?

What half-reaction occurs in compartment A?

(b) What half-reaction occurs in compartment B?

(c) Write the net redox reaction.

(d) What is the cell potential?

Answer 1

In Galvanic cell, cathode is positive electrode where reduction occurs and

an ode is negative electr ode where oxidation occurs. The cell potential is always

positive as there is a spontaneous chemical reaction generates electricity.

The electrode in compartment \(A\) is positive electr ode. Therefore, it is a cathode.

Reduction half-reaction occurs in compartment \(A\).

$$ \mathrm{Fe}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Fe} $$

(b) The electrode in compartment \(B\) is negative electrode. Therefore, it is a anode.

Oxidation half-reaction occurs in compartment B.

$$ \mathrm{Zn} \rightarrow \mathrm{Zn}^{2+}+2 \mathrm{e}^{-} $$

(c)

Net redox reaction:

$$ \mathrm{Zn}+\mathrm{Fe}^{2+} \rightarrow \mathrm{Zn}^{2+}+\mathrm{Fe} $$

(d)

$$ \begin{aligned} E_{\mathrm{cell}}^{0} &=E^{0} \text { (reduction) }-E^{0} \text { (oxidation) } \\ &=E_{\mathrm{Fe}^{++} / \mathrm{Fe}}^{0}-E_{\mathrm{m}^{2+} / \mathrm{m}}^{0} \\ &=(-0.44 \mathrm{~V})-(-0.762 \mathrm{~V}) \\ &=+0.32 \mathrm{~V} \end{aligned} $$