## Help on problem 14.17

tobeylee_1C
Posts: 10
Joined: Sat Jul 23, 2016 3:00 am

### Help on problem 14.17

(a) Write balanced half-reactions for the redox reaction of acidified solution of potassium permanganate and iron(II) chloride. (b) Write the balanced equation for the cell reaction and devise a galvanic cell to study the reaction (write its cell diagram).

I got stuck on this problem. especially on find the half reactions. Any help will be appreciated.

Caity Colt 2N
Posts: 10
Joined: Wed Sep 21, 2016 2:59 pm

### Re: Help on problem 14.17

a.) MnO4-(aq) + H+(aq) + 5e- Mn2+(aq) + 4H2O(l) (cathode)
5[Fe2+(aq) Fe3+(aq) + e-] (anode)

b.) MnO4-(aq) + 5Fe2+(aq) + 8H+(aq) Mn2+(aq) +5Fe3+(aq) +4H2O(l)

Manpreet Singh 1N
Posts: 41
Joined: Wed Sep 21, 2016 2:59 pm
Been upvoted: 1 time

### Re: Help on problem 14.17

We also multiple the second half-reaction by 5 because we want the electrons to cancel out, so we are left with the only the molecules.

danae_blodgett_1H
Posts: 18
Joined: Sat Jul 23, 2016 3:00 am

### Re: Help on problem 14.17

Can you leave it without dividing by 5 and get full credit? Or would it be wrong?

Natalie Rotstein 3J
Posts: 20
Joined: Wed Sep 21, 2016 2:59 pm

### Re: Help on problem 14.17

How do we know that the permanganate becomes a manganese ion and doesn't just lose electrons to the iron?