Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1) The cathode reaction is: ALSO, please choose FROM or TO for the following! In

ID: 511972 • Letter: 1

Question

1)



The cathode reaction is:


ALSO, please choose FROM or TO for the following!


In the external circuit, electrons migrate _____(from/to) the Pb|Pb2+ electrode _____(from/to) the I-|I2 electrode.

In the salt bridge, anions migrate _____(from/to) the Pb|Pb2+ compartment _____(from/to) the I-|I2 compartment.

2)


A voltaic cell is constructed in which the anode is a Fe2+|Fe3+ half cell and the cathode is a Br-|Br2 half cell. The half-cell compartments are connected by a salt bridge.

(Use the lowest possible coefficients. Use the pull-down boxes to specify states such as (aq) or (s). If a box is not needed, leave it blank.)

The anode reaction is:



The cathode reaction is:



The net cell reaction is:

(aq)(s)(l)(g) + (aq)(s)(l)(g)      (aq)(s)(l)(g) + (aq)(s)(l)(g)

Explanation / Answer

1) oxidation takes place at the anode

so

Anode reaction :

Pb (s) ---> Pb+2 (aq) + 2e-

cathode reaction :

I2 (s) + 2e- ---> 2I- (aq)


a) from , to

b) to , from

2)

oxidation takes place at anode

anode reaction :

Fe+2 (aq) ---> Fe+3 (aq) + e-

reduction takes place at cathode

Cathode reaction :

Br2 (l) + 2e- ---> 2 Br- (aq)

net cell reaction :

2 Fe+2 (aq) + Br2 (l) --> 2 Fe+3 (aq) + 2 Br- (aq)