Hi, I would like to know if I did this problem correctly. Your help would be greatly appreciated!
"Chlorine, Cl2, is produced commercially by the electrolysis of aqueous sodium chloride. The anode reaction is
2Cl-(aq)---> Cl2(g) + 2e-
How long will it take to produce 2.45kg of chlorine if the current is 5.00 x 10^2A?
This is what I did:
2.45kg Cl2 x 1000kg/1kg Cl2 X 1 mol Cl2/70.9g Cl2 x 2 mol e-/1 mol Cl2 x 96,500C/1 mol e-
then I divided 5.00x10^2 from 6.67x10^7, and I got 133400 seconds.
I apologize if the steps I took look jumbled up since I typed it.
Thanks!
Looks ok to me and I get the 6.67E7 BUT when I divide that by 500 I obtain 13,338 seconds. That should be rounded, of course, but yout answer is 10x that. Try the arithmetic again.
I keep getting my same answer, 133,400. I don't know what I could be doing wrong!
I apologize. I get 6.67E6 for the first number and that divided by 500 = 13,338 seconds. The number is 6,669,252.468 on my calculator. See if you get that number. You may just be counting the places wrong which is what I did when I responded first with the E7 value.
Your calculations are correct except for the division at the end. Let's walk through the steps to verify the correct answer.
First, convert the mass of chlorine from kilograms to grams:
2.45 kg Cl2 x 1000 g/1 kg Cl2 = 2450 g Cl2
Next, convert the mass of chlorine from grams to moles:
2450 g Cl2 x 1 mol Cl2/70.9 g Cl2 = 34.582 mol Cl2
Then, use the stoichiometry of the reaction to convert moles of chlorine to moles of electrons:
34.582 mol Cl2 x 2 mol e-/1 mol Cl2 = 69.164 mol e-
Finally, calculate the time required using Faraday's law of electrolysis:
69.164 mol e- x (96,500 C/1 mol e-) / (5.00 x 10^2 A) = 1333.28 s
So, it will take approximately 1333.28 seconds to produce 2.45 kg of chlorine gas.