The mass of substance deposited during electrolysis
1. Calculate the mass of silver deposited at the cathode when a current of 0.50 A is
passed through a silver nitrate solution for 15 minutes.
2. Calculate the mass of copper deposited at the cathode when a current of 2.00 A
is passed through a copper(II) sulfate solution for 10 minutes.
3. Chromium is electroplated from an acidic solution containing Cr3+. Calculate the
mass of chromium deposited when a current of 1.80 A is applied for 45 minutes.
4. During the electrolysis of molten calcium chloride, calculate the amount of
calcium (in grams) deposited at the cathode when a current of 5.0 A is passed for
2 hours.
Calculating amount of substance produced during electrolysis
1. Calculate the mass of hydrogen produced at r.t.p. when a concentrated aqueous
solution of sulfuric acid is electrolyzed for 15.0 min using a current of 1.40 A.1
mole of gas occupies 24.0 L
2. Calculate the mass of oxygen produced at r.t.p. when a concentrated aqueous
solution of sulfuric acid, H2SO4, is electrolyzed for 30.0 min using a current of
0.50 A.
3. Calculate the volume of hydrogen gas produced at r.t.p. when an aqueous
solution of hydrochloric acid (HCl) is electrolyzed for 10.0 minutes using a current
of 1.50 A. Assume 1 mole of gas occupies 24.0 L at r.t.p.
4. Calculate the volume of oxygen produced at r.t.p. when a concentrated aqueous
solution of sodium sulfate is electrolyzed for 55.0 min using a current of 0.70 A.
The Nernst equation - reactions at nonstandard conditions
1. Calculate the value of the electrode potential at 298 K of a Ni(s)/Ni2+(aq)
electrode that has a concentration of Ni2+(aq) ions of 1.5 mol dm–3. E °= –0.25
V.
2. Calculate the electrode potential of a silver/silver ion electrode, Ag(s)/Ag+(aq), at
0 °C when the concentration of Ag+(aq) ions is 0.0002 mol/L . E° = +0.80 V.