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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Fish200398 on March 22, 2020, 07:22:19 AM

Title: Electrolysis of cucl2
Post by: Fish200398 on March 22, 2020, 07:22:19 AM
Using 2.5 Amperes, pt electrode , and 112 ml gas generated.
How many charges flow?

 Cl2 gas generated in anode
 Cu (s) formed in chatode

Can i assume 112 ml at STP ?
112 ml Cl2 means 0.05 moles of Cl2 means involved 0.05 F electrons.

1 F requires 96500 charges
Means 0.05 F requires 4.825 C

Is it true?
Title: Re: Electrolysis of cucl2
Post by: Borek on March 22, 2020, 07:51:52 AM
Using 2.5 Amperes, pt electrode , and 112 ml gas generated.
How many charges flow?

 Cl2 gas generated in anode
 Cu (s) formed in chatode

Can i assume 112 ml at STP ?

If no other information is given that's better than nothing.

Quote
112 ml Cl2 means 0.05 moles of Cl2 means involved 0.05 F electrons.

No. You are on a right track, but you made two errors. One is just a simple math, the other is related to the reaction equation.

Quote
1 F requires 96500 charges

Not "charges", coulombs. Just like you don't say water boils at 100 temperatures nor Moon is 384 thousands distances from Earth. Coulomb is a charge unit just like kilometer is a distance/length unit, and degree (be it Celsius, or Fahrenheit) or Kelvin are units of temperature.

Quote
Means 0.05 F requires 4.825 C

Is it true?

You not only managed to propagate all previous mistakes in your calculations (that would be understandable) but you again failed at math.
Title: Re: Electrolysis of cucl2
Post by: Fish200398 on March 22, 2020, 09:27:41 AM
2Cl- = Cl2 + 2e

0.005 moles gas Cl2, means 0.005 F electrons
Means 482.5 C flows through the electrolysis

Is it true?
Title: Re: Electrolysis of cucl2
Post by: chenbeier on March 22, 2020, 10:28:04 AM
Mol ist not the same like Farad.

Q = n* z* F

 Charge =  mol* amount of electron in reaction * Faraday constant.

Fill in with your values.
Title: Re: Electrolysis of cucl2
Post by: Fish200398 on March 22, 2020, 12:05:43 PM
I just realized the mistake is Cl2 and electrons has coefficient of 1:2
So there are 0.01 F.
Btw, its true right that Cl2 was formed in anode?
Title: Re: Electrolysis of cucl2
Post by: chenbeier on March 22, 2020, 12:14:32 PM
What is 0,01 F?

You have 112 ml   = 0,112 l Cl2

How much mol is it?

This has to be multiplited with die amount of transferred electrons and the Faraday constant.

Die Value will be in Coulomb.
Title: Re: Electrolysis of cucl2
Post by: Fish200398 on March 22, 2020, 02:22:59 PM
At STP 1 mol gas = 22.4 L
0.112 L = 0.005 moles Cl2
Title: Re: Electrolysis of cucl2
Post by: chenbeier on March 22, 2020, 03:08:53 PM
Correct, then you can calculate the charge in Coulomb.