AP Chemistry 9.9 Cell Potential and Free Energy Questions

Practice AP Chemistry Unit 9.9 questions on calculating cell potential from half-reactions and relating its sign to ΔG° and favorability.

Covered syllabus points

9.9.A—Explain whether an electrochemical cell is thermodynamically favored, based on its standard cell potential and…

[Maximum number: 1]

A scientist constructs a galvanic cell as shown in the diagram. As the cell operates, the $\mathrm{Zn}(s)$ electrode increases in mass and the $\mathrm{Al}(s)$ electrode decreases in mass. A data table with the standard reduction potentials for the substances follows the diagram.

The standard Zn/Al cell has a value of $E_{\text {cell }}^{\circ}$ equal to 0.90 V. The scientist needs a galvanic cell that produces a greater voltage. The scientist has access to the chemical systems in the table.

If the scientist uses the Zn half-cell and one of the other options from the table, what is the MAXIMUM voltage that could be generated at standard conditions?

For the correct calculated value.

Point 04

Examples of acceptable responses may include the following:

- $E_{\text {cell }}^{\circ}=1.50 \mathrm{~V}+0.76 \mathrm{~V}=2.26 \mathrm{~V}$

- $\mathrm{Au}^{3+}(a q)+3 e^{-} \rightarrow \mathrm{Au}(s)+1.50 \mathrm{~V}$ $\mathrm{Zn}(s) \rightarrow \mathrm{Zn}^{2+}(a q)+2 e^{-} \quad+0.76 \mathrm{~V}$ $E_{\text {cell }}^{\circ}=2.26 \mathrm{~V}$

All question bank results loaded

Covered syllabus points

Question 1