A student contrructs an electrochemical cell using Zn/Zn^2+ half cell and a Cu/Cu^2+ half cell. The zinc electrode is immersed in a zinc sulfate solution and copper electride is immersed in copper (2) sulfate solution.
If each 56.0mL solution has a concentration 1.00mol/L, calculate the mass change at each electrode (assume the cell is able to use all of one solution).
To calculate the mass change at each electrode, we need to determine the moles of each element involved in the reaction at each electrode.
Given that the volume of each solution is 56.0 mL (or 0.056 L) and the concentration of each solution is 1.00 mol/L, we can find the number of moles of Zn and Cu in each half-cell.
For the zinc half-cell:
moles of Zn = concentration * volume
moles of Zn = 1.00 mol/L * 0.056 L
moles of Zn = 0.056 mol
For the copper half-cell:
moles of Cu = concentration * volume
moles of Cu = 1.00 mol/L * 0.056 L
moles of Cu = 0.056 mol
Next, we need to determine the balanced redox reaction that occurs in the electrochemical cell. The balanced reaction between zinc and copper(II) ions can be represented as follows:
Zn(s) + Cu^2+(aq) -> Zn^2+(aq) + Cu(s)
From the balanced reaction, we can see that for every mole of zinc that reacts, one mole of copper is produced.
Therefore, the mass change at the zinc electrode (Zn(s)) can be calculated as follows:
mass change of Zn = moles of Zn * molar mass of Zn
mass change of Zn = 0.056 mol * 65.38 g/mol
mass change of Zn = 3.654 g
The mass change at the zinc electrode is 3.654 g.
Similarly, the mass change at the copper electrode (Cu(s)) can be calculated as follows:
mass change of Cu = moles of Cu * molar mass of Cu
mass change of Cu = 0.056 mol * 63.55 g/mol
mass change of Cu = 3.553 g
The mass change at the copper electrode is 3.553 g.
Therefore, the mass change at each electrode is 3.654 g for the zinc electrode and 3.553 g for the copper electrode.