|AP Chemistry - Electrochemistry Worksheet #7|
charges do the anode and the cathode carry in an electrolytic cell?
|2.||Why must electrolysis
occur in order for electrolytic conduction to continue?
|3.||Write the anode,
cathode, and overall reactions for the electrolysis of molten NaCl.
to the pH of the solution near the cathode and anode during the electrolysis
|5.||Write the anode
reaction for the electrolysis of an aqueous solution that contains
(b) Br- and
(c) NO3- and Br-
would we expect at the electrodes if a solution containing both KBr and Cu(NO3)2
|7.||How many Farads
are required to reduce 10 g of calcium from melted calcium chloride?
|8.||A current of
5.0 amp is passed through melted KCl for 1000 sec. How many grams
of potassium are produced?
|9.||How much time
is required to reduce 20.0 g of silver from a solution of silver nitrate,
using 15.0 amp of current?
|10.||a) How many grams
of copper are deposited from a plating bath by a current of 3.0 amperes
flowing for a period of 2.0 hours?
b) How many litres of oxygen gas will be evolved at the anode if the temperature is 27oC and the pressure is 98.6 kPa?
c) If the cell originally contained 1.0 litre of 0.20 M CuSO4 and a platinum (inert) anode, what is the concentration of CuSO4 after the electrolysis assuming no volume change?
d) If the anode is a bar of copper, what is the concentration of CuSO4 after the electrolysis?
|11.||How many litres
of H2 are evolved at 20oC and 99 kPa when 2.0 amps
is passed for 3.0 hours through a cell containing sulphuric acid?
|12.||a) Explain why
the silver and gold found in blister(impure) copper do not go into solution
when the anode disintegrated during the electrolytic refining of copper.
b) If Ag+ ions were present in the electrolyte, would they interfere with the production of pure copper cathodes? Explain.
c) If Al3+ ions were present, would they interfere with the production of pure copper cathodes? Explain.
|13.||How many coulombs
are passed through an electrolysis cell by
(a) a current of 4.00 A for 600 s?
(b) a current of 10.0 A for 20 min?
(c) a current of 1.5 A for 6.00 hr?
How many faradays correspond to the answers above?
|14.||How many faradays
are required to
(a) reduce 0.20 mol Fe2+ to Fe?
(b) oxidize 0.70 mol Cl- to Cl2?
(c) reduce 1.50 mol Cr3+ to Cr?
(d) oxidize 1.0 X 10-2 mol Mn2+ to MnO4-?
|15.||How many grams
of Fe(OH)2 are produced at an iron anode when a basic solution
undergoes electrolysis at a current of 12.0 A for 10.0 min?
|16.||How many faradays
are required to
(a) produce 5.00 g Mg from molten MgCl2?
(b) form 41.0 g Cu from CuSO4 solution?
|17.||How many millilitres
of gaseous H2, measured at STP, would be produced at the
cathode in the electrolysis of water with a current of 1.50 A for 5.00
|18.||How many moles
of Cr3+ would be reduced to Cr by the same amount of electricity
that produces 10.0 g Ag from a AgNO3 solution?
|19.||A solution of
NaCl in water was electrolyzed with a current of 3.00 A for 10.0 min.
How many millilitres of 0.100 M HCl would be required to neutralize the resulting
|20.||How many hours
would it take to produce 25.0 g of metallic chromium by the electrolytic
reduction of Cr3+ with a current of 1.25 A?
|21.||How many hours
would it take to generate 25.0 g lead from PbSO4 during the
charging of a storage battery using a current of 0.50 A? The half-reaction
PbSO4 + 2 e- ---> Pb + SO42-
|21.||How many amperes
would be needed to produce 48.0 g of magnesium during the electrolysis
of molten MgCl2 in 1.00 hr?
|22.||A large electrolysis
cell that produces metallic aluminum from Al2O3 by
the Hall process is capable of yielding 409 kg of aluminum in 24 hr.
What current is required?
|23.||How many grams
of Cl2 would be produced in the electrolysis of NaCl by a current
of 2.50 A for 40.0 min?
|24.||A solution containing
vanadium (chemical symbol - V) in an unknown oxidation state was electrolyzed
with a current of 1.50 A for 30 min. It was found that 0.475 g of
V was deposited on the cathode.
(a) How many equivalents of V were deposited?
(b) How many moles of V were deposited?
(c) What was the original oxidation state of the V ion?
|25.||Predict the products
that will appear if a solution of Cu(NO3)3 is electrolyzed.
Give the net cell reaction.