# Worksheet: The Nernst Equation

In this worksheet, we will practice using the Nernst equation to calculate reduction potentials under nonstandard concentrations.

Q1:

A battery is dead when it has no cell potential. Consider a battery with the overall reaction: . The standard electrode potentials for the half-cells in this battery are given in the table.

Half-equation Standard electrode potential, 𝐸⦵ (V) C u ( ) + 2 e C u ( ) 2 + – a q s A g ( ) + e A g ( ) + – a q s + 0 . 3 4 0 + 0 . 7 9 9 6

To 2 significant figures, what is the value of when this battery is dead at 298.15 K?

• A
• B
• C
• D
• E

If a particular dead battery is found to have = 0.11 M, what is the concentration of silver ions?

• A M
• B M
• C M
• D 0.22 M
• E 0.11 M

Q2:

Calculate to 2 significant figures the equilibrium constant at for the following reaction.

Note that each standard electrode potential is expressed per mole of the half-reaction shown in the table.

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) 2 H ( ) + 2 e H ( ) + – 2 a q g 2 H O ( ) + 2 e H ( ) + 2 O H ( ) 2 – 2 – l g a q 0.000 − 0 . 8 2 7 7
• A
• B
• C
• D
• E

Q3:

Using the standard electrode potentials shown in the table, calculate to 2 significant figures the equilibrium constant at 373 K for the following reaction.

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) H g ( ) + 2 e H g ( ) 2 + – a q l [ H g B r ] ( ) + 2 e H g ( ) + 4 B r ( ) 4 2 – – – a q l a q + 0 . 8 5 1 + 0 . 2 1
• A
• B
• C
• D
• E

Q4:

Using the standard electrode potentials shown in the table, calculate to 2 significant figures the equilibrium constant at 373 K for the following reaction.

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) C d ( ) + 2 e C d ( ) 2 + – a q s C d S ( ) + 2 e C d ( ) + S ( ) s s a q – 2 – – 0 . 4 0 3 0 – 1 . 1 7
• A
• B
• C
• D
• E

Q5:

Using the standard electrode potentials shown in the table, calculate to 2 significant figures the equilibrium constant at 298.15 K for the following reaction.

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) A g ( ) + e A g ( ) + – a q s A g C l ( ) + e A g ( ) + C l ( ) s s a q – – + 0 . 7 9 9 6 + 0 . 2 2 2 3 3
• A
• B
• C
• D
• E

Q6:

In the half-cells of an electrochemical cell, 1.00 M aqueous bromide ions are oxidized to 0.110 M bromine and 0.0230 M aluminum ions are reduced to aluminum metal. Using the standard electrode potentials shown in the table, calculate to 3 decimal places the cell potential for the cell at 298.15 K. Note that standard electrode potentials are measured using 1.00 M solutions of the reacting ions.

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) B r ( ) + 2 e 2 B r ( ) 2 – – a q a q A l ( ) + 3 e A l ( ) 3 + – a q s + 1 . 0 8 7 3 − 1 . 6 6 2

Q7:

The half-cells of a galvanic cell consist of an aluminum electrode in a 0.0150 M aluminum nitrate solution and a nickel electrode in a 0.250 M nickel(II) nitrate solution. Using the standard electrode potentials shown in the table, calculate to 2 decimal places the cell potential for the galvanic cell at 298.15 K. Note that standard electrode potentials are measured using 1.00 M solutions of the reacting ions.

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) A l ( ) + 3 e A l ( ) 3 + – a q s N i ( ) + 2 e N i ( ) 2 + – a q s – 1 . 6 6 2 – 0 . 2 5 7

Q8:

Using the standard electrode potentials shown in the table, calculate to 2 decimal places the cell potential at 298.15 K for the cell with the following overall reaction.

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) H g S ( ) + 2 e H g ( ) + S ( ) s l a q – 2 – A g ( ) + e A g ( ) + – a q s – 0 . 7 0 + 0 . 7 9 9 6

Q9:

Using the standard electrode potential data in the table, calculate the standard cell potential for the following reaction at 298 K.

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) C o ( ) + 2 e C o ( ) 2 + – a q s F e ( ) + 2 e F e ( ) 2 + – a q s − 0 . 2 8 − 0 . 4 4 7

Q10:

Calculate to 3 significant figures the cell potential for the following reaction at 298 K?

Half-Equation Standard Electrode Potential, 𝐸⦵ (V) A l ( ) + 3 e A l ( ) 3 + – a q s C u ( ) + 2 e C u ( ) 2 + – a q s – 1 . 6 6 2 + 0 . 3 4 0