The voltaic cell described by the cell notation has a standard emf (electromotive force) of 0.94 V. Calculate the value (J) for the maximum electrical work that the cell can do under standard conditions. Round your answer to 3 significant figures.
Pt(s) / Br-(aq) / Br2(l) // S2O82-(aq), SO42-(aq) / Pt(s)
To calculate the maximum electrical work (ΔG) that the cell can do under standard conditions, we need to use the standard emf (E°) of the cell.
The formula to calculate the maximum electrical work is:
ΔG = -nFE°
Where:
- ΔG is the maximum electrical work
- n is the number of moles of electrons transferred in the balanced equation for the cell reaction
- F is the Faraday constant (96485 C/mol)
- E° is the standard emf of the cell.
From the cell notation, we can deduce the balanced equation for the cell reaction:
Br-(aq) + Br2(l) + 2e- → 2Br-(aq)
In this reaction, 2 moles of electrons are transferred.
Now, let's calculate the maximum electrical work:
ΔG = -nFE°
= -(2 mol)(96485 C/mol)(0.94 V)
= -182717.4 J
Rounding this value to 3 significant figures gives:
ΔG ≈ -1.83 x 10^5 J
Therefore, the maximum electrical work that the cell can do under standard conditions is approximately -1.83 x 10^5 J.