1. I
CHEMISTRY 3
ELECTROCr{EMISI'RY - Quantitative Aspects of Electroh'sis
Problem Set:
of
deposited from a solulion
l. Horv many grams of the corresponding metal-s l"*Jg.b.
eachofthefollorvingionsbl'thepassageof l.0x l03coulombsofelectricchargein
an electroll4ic cell?
(c) Fe*2 (d) Al.3
(a)cui2 (b)
49.
in 0.500 liter of 0' 100 M
2. Horv long rvould it take to electrodeposit all of the Ctt*2
CuSOr rvith a current of 2.20 amP?
96,500 coulornbs pass
3. Calculate (a) the number of grams of Clz liberated rvhen
at STP'
throush an HCI solution, una (U) the volume of Hz liberated
solution for 2'0 hours
I
T. A current of 3.0 amp is passed through an aqueous HzSOr
volume of hy'drogen liberated
Calculate (a) the rveighiol'oxygen liberate6 and (b) the
at STP.
amp to deposit 127 grams
). Calculate the number of hours required for a current of 4-0
of electrons is involved in
of copper from a solution of copper sulfate. What number
the above electrolYsis?
grams of iron from a solution of
6. Horv many.coulombs will be required to plate out 5.6
Iron (III) chloride?
the cathode rvhen 0' 10 g of
Calculate the number of electrons that must be gained at
the oxidation state of the
silver is electroplated on a metal serving tray. (Assume.that
are required to provide this
silr,er in the plating solution is +1). Ho* many coulombs
number of electrons? Hos'long must a 1.5-ampere current
flou'to suppl'v this number
of coulornbs?
in a $'ater
A salt known to contain platinum and chloride ions only was electrolyzed
The cathode rvas then
solution until 300 coulombs had passed through the solution'
deposit of elemental
,e*oued, dried and weighed. The gain in weight due to the
platinum was 0.152 g. Write the formula of the salt'
JOma