CHEM_167_Houk_grantd_SI_Session_34_4-28-13_answers

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Ch 13.6-13.7
Supplemental Instruction
Iowa State University
	Leader:
	Grant DeRocher
	
	Course:
	Chem 167
	
	Instructor:
	Houk
	
	Date:
	04/28/13
Q = I x T 		1 watt = 1 J/s 		1A= 1 C/s 		F=96,485 C/mol
1. If a current of 15 A is run through an electrolysis cell for 2.0 hours, how many moles of electrons have moved?
15 A x 2.0 hours x 3600seconds/1hour x 1C/1 A*s x 1 mol e-/96485 C = 1.1 mol e-
2. If a barrel plating run uses 200.0 A for exactly 6 hours for an electroplaning application at 0.30 V, how many kilowatt-hours have been used in the run? If the voltage is 0.90V what is the power usage(in kWh)?
 
For 0.90 V, 
3. In a copper plating experiment in which copper metal is depositied from copper (II) ion solution, the system is run for 2.6 hours at a current of 12.0 A. What mass of copper is deposited?
Cu2+ + 2e- 		Cu(s)
4. Tin-plated steel is used for “tin” cans. Suppose that in the production of sheets of tin-plate steel, a line at a factory operates at a current of 100.0 A for exactly 8 hours on a continuously fed sheet of unplated steel. If the electrolyte contains tin(II) ions, what is the total mass of tin that has plated out in this operation?
Sn2+ + e- 	Sn(s) 
5. If a plating line that deposits nickel(from NiCl2 solutions) at a voltage of 0.40 volts with a current of 400 A and a total mass of 49.0 kg of nickel deposited, what is the minimum number of kWh consumed in this process?
Ni2+ + 2e- 		Ni(s)