Unit 10: Electrochemistry

21. The term “electrolytic cell” refers to a cell where:

a) Chemical energy is converted into electrical energy
b) Electrical energy is used to drive a non-spontaneous reaction
c) The reaction is spontaneous and produces electricity
d) The electrodes are made of non-metallic materials
Answer: b) Electrical energy is used to drive a non-spontaneous reaction

22. In an electrolytic cell, the anode is the electrode where:

a) Reduction occurs
b) Oxidation occurs
c) The electrolyte is present
d) The external power source is connected
Answer: b) Oxidation occurs

23. The purpose of a salt bridge in an electrolytic cell is:

a) To prevent the flow of ions
b) To provide a medium for the electrolytic reaction
c) To maintain electrical neutrality by allowing ion migration
d) To increase the cell potential
Answer: c) To maintain electrical neutrality by allowing ion migration

24. The Faraday constant (F) represents:

a) The charge of a single electron
b) The number of moles of electrons per unit charge
c) The total charge carried by one mole of electrons
d) The rate of an electrochemical reaction
Answer: c) The total charge carried by one mole of electrons

25. The relationship between Gibbs free energy change (ΔG) and cell potential (E_cell) is given by:

a) ΔG = -nFE_cell
b) ΔG = nFE_cell
c) ΔG = nFE_cell – RTlnQ
d) ΔG = RTlnQ – nFE_cell
Answer: a) ΔG = -nFE_cell

26. The unit of cell potential (E_cell) is:

a) Joules
b) Coulombs
c) Volts
d) Amperes
Answer: c) Volts

27. In a concentration cell, the electrode with higher concentration of ions:

a) Acts as the anode
b) Acts as the cathode
c) Has a lower electrode potential
d) Has no effect on the cell potential
Answer: b) Acts as the cathode

28. The electrolysis of water produces:

a) Oxygen at the anode and hydrogen at the cathode
b) Hydrogen at the anode and oxygen at the cathode
c) Hydrogen at both electrodes
d) Oxygen at both electrodes
Answer: a) Oxygen at the anode and hydrogen at the cathode

29. In a galvanic cell, the flow of electrons is from:

a) The anode to the cathode
b) The cathode to the anode
c) The salt bridge to the anode
d) The external circuit to the electrolyte
Answer: a) The anode to the cathode

30. The reduction potential for the half-reaction can be determined experimentally using:

a) The Nernst equation
b) A standard hydrogen electrode
c) The Arrhenius equation
d) The van der Waals equation
Answer: b) A standard hydrogen electrode