Problem 44
Which product, Ca or \(\mathrm{H}_{2}\), is more likely to form at the cathode in the electrolysis of \(\mathrm{CaCl}_{2}\) ? Explain your reasoning.
Problem 45
An aqueous solution of KBr is placed in a beaker with two inert platinum electrodes. When the cell is attached to an external source of electrical energy, electrolysis occurs. (a) Hydrogen gas and hydroxide ion form at the cathode Write an equation for the halfreaction that occurs at this electrode. (b) Bromine is the primary product at the anode. Write an equation for its formation.
Problem 46
An aqueous solution of \(\mathrm{Na}_{2} \mathrm{S}\) is placed in a beaker with two inert platinum electrodes. When the cell is attached to an external battery, electrolysis OCCurs. (a) Hydrogen gas and hydroxide ion form at the cathode Write an equation for the halfreaction that occurs at this electrode. (b) Sulfur is the primary product at the anode. Write an equation for its formation.
Problem 47
In the electrolysis of a solution containing \(\mathrm{Ni}^{2+}(\mathrm{aq}),\) metallic \(\mathrm{Ni}(\mathrm{s})\) deposits on the cathode. Using a current of 0.150 A for 12.2 minutes, what mass of nickel will form?
Problem 48
In the electrolysis of a solution containing \(\mathrm{Ag}^{+}(\mathrm{aq}),\) metallic \(\mathrm{Ag}(\mathrm{s})\) deposits on the cathode Using a current of 1.12 A for 2.40 hours, what mass of silver forms?
Problem 49
Electrolysis of a solution of \(\mathrm{CuSO}_{4}\) (aq) to give copper metal is carried out using a current of 0.66 A. How long should electrolysis continue to produce \(0.50 \mathrm{g}\) of copper?
Problem 50
Electrolysis of a solution of \(\mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}(\mathrm{aq})\) to give zinc metal is carried out using a current of \(2.12 \mathrm{A}\) How long should electrolysis continue in order to prepare \(2.5 \mathrm{g}\) of zinc?
Problem 51
A voltaic cell can be built using the reaction between Al metal and \(\mathrm{O}_{2}\) from the air. If the Al anode of this cell consists of 84 g of aluminum, how many hours can the cell produce \(1.0 \mathrm{A}\) of electricity, assuming an unlimited supply of \(\mathbf{O}_{2} ?\)
Problem 53
Use \(E^{\circ}\) values to predict which of the following metals, if coated on iron, will provide cathodic protection against corrosion to iron. (a) Cu (b) \(\mathrm{Mg}\) (c) Ni (d) Sn
Problem 54
Use \(E^{\circ}\) values to predict which of the following metals, if coated on nickel, will provide cathodic protection against corrosion to nickel. (a) Cu (b) \(\mathrm{Mg}\) (c) Zn (d) \(\mathrm{Cr}\)
