I need help with both 19 and 20, the answers are underline, I just don\'t know h

Question

I need help with both 19 and 20, the answers are underline, I just don't know how to do them so if you can please show work and thank you

SS57 I U 19. If 20.0 Amps are applied to a solution containing Al3+ for two weeks, how many grams of solid aluminum would plate out of solution? a. 5.04 ng b. 443 pug 54.0g d 2.26 kg e. 5.04 kg 20. What is the equilibrium constant for a reaction at 25.0°C, involving the transfer of three electrons if the standard cell potential is +1.85 Volts? a 7.35-1093 b. 1.95-1031 c. 1.00 d. 5.13-10-32 e. 1.36·10-94

Explanation / Answer

the electrolysis expression is:

Al3+ + 3e- ------> Al

1 mol of Al requires 3 mol of electron

1 mol of electron = 96485 C

So,1 mol of Al requires 289455 C

let us calculate the charge passed:

t = 336.0 hr = 336.0*3600 s = 1209600 s

time, t = 2 weeks

= 2*7*24 h

= 336 h

= 336*3600 s

= 1209600s

Q = I*t

= 20A * 1209600s

= 24192000 C

mol of Al plated = 24192000/289455 = 83.57776 mol

Molar mass of Al = 26.98 g/mol

mass of Al = number of mol * molar mass

= 83.57776 * 26.98

= 2255 g

= 2.26 Kg

Answer: 2.26 Kg

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