Electrolytic cells and electrolysis Knowledge-Based Download PDF

Questions

1. 1.

   An electrolytic cell contains an aqueous solution with equimolar concentrations of $\text{Ag}^+$, $\text{Cu}^{2+}$, and $\text{Ni}^{2+}$ ions, whose standard reduction potentials are $+0.80\text{ V}$, $+0.34\text{ V}$, and $-0.26\text{ V}$, respectively. Which metal is deposited first at the cathode as an external voltage is applied?

   • A) $\text{Ag}$
   • B) $\text{Cu}$
   • C) $\text{Ni}$
   • D) $\text{H}_2$
2. 2.

   A constant electric current of 9.65 A is passed through an electrolytic cell containing an aqueous silver nitrate (AgNO3) solution for 1000 seconds. What mass of silver metal is deposited at the cathode? (Molar mass of Ag = 108 g/mol; Faraday constant, F = 96,500 C/mol)

   • A) 1.08 g
   • B) 5.40 g
   • C) 10.8 g
   • D) 21.6 g
3. 3.

   How many moles of electrons must pass through an electrolytic cell to produce 2.0 moles of aluminum metal at the cathode during the electrolysis of molten aluminum oxide ($\text{Al}_2\text{O}_3$)?

   • A) 3.0 moles
   • B) 6.0 moles
   • C) 2.0 moles
   • D) 1.5 moles
4. 4.

   During the electrolysis of molten sodium chloride (NaCl), which substances are produced at the cathode and the anode, respectively?

   • A) Sodium metal at the cathode and chlorine gas at the anode
   • B) Chlorine gas at the cathode and sodium metal at the anode
   • C) Hydrogen gas at the cathode and chlorine gas at the anode
   • D) Sodium metal at the cathode and oxygen gas at the anode
5. 5.

   Which of the following statements correctly describes the operation of an electrolytic cell?

   • A) Oxidation occurs at the negative electrode, which acts as the cathode.
   • B) Chemical energy released from a spontaneous redox process is converted into electrical energy.
   • C) Electrons travel through the external circuit from the cathode to the anode.
   • D) An external power source drives a nonspontaneous redox reaction by supplying electrons to the cathode.