Making Galvanic Cells Lab

3) The salt bridge allows the cell to continue to function. K+ or NO3

– can move into one of the half cells to balance the charge created by + metal ions forming or leaving solution.

4) No. We did not get the same values in the lab

No bridge Voltage Points to Deposit

Cu – Al 0 V 2.0 V Cu Cu

Cu – Zn 0 V 1.1 V Cu Cu

Al – Zn 0 V 0.9 V Zn Zn

Cu – Zn cell

Zn Zn2+ + 2e– (oxidation - LEO)Cu2+ + 2e– Cu (reduction - GER)

Cu2+ + Zn Cu + Zn2+

Electron flow

Salt bridgeCu (+) Zn (–)

Cu2+ Zn2+

Al – Zn cell

Zn2+ + 2e– Zn (reduction - GER)Al Al3+ + 3e– (oxidation - LEO)

2Al + 3Zn2+ 2Al3+ + 3Zn

Electron flow

Salt bridge Zn (+) Al (–)

Zn2+Al3+

Making Galvanic Cells Lab

AlDepositCuDeposit

AlPoints toCuPoints to

0.530 sec 0.930 sec

0.50 sec 0.90 sec

0No bridge0No bridge

voltageAl-ZnvoltageCu-Zn

3) The salt bridge allows the cell to continue to function. K+ or NO3

– can move into one of the half cells to balance the charge created by + metal ions forming or leaving solution.

4) No. We did not get the same values in the labFor more lessons, visit www.chalkbored.com