Electrochemical cells Flashcards
1
Q
an electrochemical cell is a device used
A
for producing an electric current from chemical reactions
2
Q
which of the following will be the negative electrode of the cell: Zn2+(aq) + 2e- ⇌ Zn(s) E⦵ = -0.76V Cu2+(aq) + 2e- ⇌ Cu(s) E⦵ = +0.34V
A
Zn2+(aq) + 2e- ⇌ Zn(s)
E⦵ = -0.76V
Cu2+(aq) + 2e- ⇌ Cu(s)
E⦵ = +0.34V
the E⦵ value for the Zn2+ | Zn half-cell is more negative, so the zinc electrode will be the negative electrode of the cell
so the electrons will flow from the zinc electrode to the copper electrode
3
Q
the conventions for shorthand notation of representing two half cells in a cell diagram are:
A
- the two reduced forms of the species are shown on the outside of the cell diagram
- the positive electrode is shown on the right-hand side of the cell diagram
- the standard hydrogen electrode is always written on the left-hand side
4
Q
the cell-diagram for the cell formed by combining the half cells below are: Zn2+(aq) + 2e- ⇌ Zn(s) E⦵ = -0.76V Cu2+(aq) + 2e- ⇌ Cu(s) E⦵ = +0.34V
A
Zn(s) | Zn2+(aq) || Cu2+(aq) | Cu(s)