Calculate the mass of Li formed by elecrolysis of molten LiCl by a current of 7.5 x 10^4 Amps flowing for a period of 24h. Assume the elecrolytic cell is 85% efficient.
I keep getting 4.6 X 10^5 grams of Li when the book has it as being 4.0 x 10 ^5. What am I doing wrong? I checked it like 12 times so don't just say adding them wrong. Tell me how you got the answer.
2007-04-04 09:31:12 · 2 answers · asked by __ 3 in Science & Mathematics ➔ Chemistry
7.5*10^4 * 3600 *24 (Charge, lets say Q)
Moles of Li+ ions = Q/96500
Actual Mass = .85*7*Q/96500 = 399 544.041 g = 3.99 x 10^5 g
or 4 x 10^5 g
2007-04-04 09:43:00 · answer #1 · answered by ag_iitkgp 7 · 0⤊ 0⤋
I won't tell you the answer, but from your information, your error is screamingly obvious; the figure of 4 x 10^5 is approximately 85% of your answer of 4.6 x 10^5.
This is accounted for by the cell efficiency!
2007-04-04 09:38:44 · answer #2 · answered by Modern Major General 7 · 0⤊ 0⤋