August 04, 2024, 05:01:36 PM
Forum Rules: Read This Before Posting

### Topic: a tough redox question  (Read 4769 times)

0 Members and 1 Guest are viewing this topic.

#### clint476

• New Member
• Posts: 3
• Mole Snacks: +0/-0
##### a tough redox question
« on: December 19, 2006, 10:31:38 AM »
Anyone got any idea how to answer part b)??
I´m stumped

6.   A current of 3A is passed for 3 hours through a solution of copper II sulphate (using copper electrodes).

(a)   Write ionic equations to show what happens at the (i) anode (ii) cathode.         [2]

(b)   Calculate the changes in mass of the cathode and anode stating whether a gain or loss.  (Show working)      [4]

#### Borek

• Mr. pH
• Deity Member
• Posts: 27754
• Mole Snacks: +1804/-411
• Gender:
• I am known to be occasionally wrong.
##### Re: a tough redox question
« Reply #1 on: December 19, 2006, 11:13:49 AM »

q = i*t?
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

#### clint476

• New Member
• Posts: 3
• Mole Snacks: +0/-0
##### Re: a tough redox question
« Reply #2 on: December 19, 2006, 11:31:48 AM »
Hi Borek,
I can calculate Q from the equation which will give me the number of coulombs of charge but how do i convert this to the mass of copper collected at the cathode, and lost at the anode??

#### Borek

• Mr. pH
• Deity Member
• Posts: 27754
• Mole Snacks: +1804/-411
• Gender:
• I am known to be occasionally wrong.
##### Re: a tough redox question
« Reply #3 on: December 19, 2006, 04:52:45 PM »
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

#### clint476

• New Member
• Posts: 3
• Mole Snacks: +0/-0
##### Re: a tough redox question
« Reply #4 on: December 20, 2006, 03:51:40 AM »
Thanks Borek. Good old faraday and his 96500C per mole!!

#### Borek

• Mr. pH
• Deity Member
• Posts: 27754
• Mole Snacks: +1804/-411
• Gender:
• I am known to be occasionally wrong.
##### Re: a tough redox question
« Reply #5 on: December 20, 2006, 04:09:38 AM »
Thanks Borek. Good old faraday and his 96500C per mole!!