Electrochemistry Pre-Tutorial Quiz 1

Oxidation is the _____________ of electrons.

• Loss

• Gain

• Sharing

• Transfer

Determine the oxidation number of chromium in CrO₄²⁻.

• +6

• +3

• +2

• 0

In an electrochemical cell, the electrons flow from the

• Anode to cathode

• Cathode to anode

What is the key difference between an electrochemical and an electrolytic cell?

• Electrochemical cells deliver alternating current; electrolytic cells deliver direct current.

• Electrochemical cells work continuously; electrolytic cells are for energy storage.

• Electrochemical cells convert electrical energy into chemical energy; electrolytic cells convert chemical energy into electrical energy.

• Electrons flow from anode to cathode in electrochemical cell; electrons flow from cathode to anode in electrochemical cell.

In an electrochemical cell, the salt bridge

• Completes the circuit so that electrons can flow through the wire

• Is soaked in an unreactive electrolyte such as KNO₃

• Maintains charge balance

• All of the above

Which of the following describes a standard hydrogen electrode correctly?

• Platinum electrode

• 1 mol dm⁻³ H₂SO₄

• 298K

• H₂(g) at 1atm

Which is the correct definition of “standard electrode potential”?

• the e.m.f. of a half-cell connected to a standard hydrogen electrode, measured at 298K with solution concentrations of 1 mol dm^-3 and gas pressures of 100kPa

• the e.m.f. of a half-cell connected to a platinum electrode, measured at 298K with solution concentrations of 1 mol dm^-3 and gas pressures of 100kPa

• the e.m.f. of a half cell connected to a platinum electrode, measured at 298K with solution concentrations of 1 mol dm^-3 and gas pressures of 100kPa and a voltmeter set at 1.00V

• the e.m.f. of a half-cell connected to a standard hydrogen electrode, measured at 298K with solution concentrations of 1 mol dm^-3 and gas pressures of 100kPa and a voltmeter set at 1.00V

In the following electrochemical cell, which half-cell is undergoing reduction?

Cu²⁺ + 2e⁻ ⇌ Cu +0.34V

Zn²⁺ + 2e⁻ ⇌ Zn −0.76V

• Cu²⁺/Cu

• Zn²⁺/Zn

An electrochemical cell was set up from a Cl₂/Cl^- half-cell and a standard hydrogen electrode (SHE). It was found that the voltmeter reading was 1.36 V and the chlorine half-cell was the positively-charged electrode. Which statement is INCORRECT?

• Both of the electrodes should be made of platinum.

• The Cl₂/Cl^- half-cell is the anode.

• As the cell operates, the pH of the solution in the SHE decreases.

• The standard redox potential for the chlorine half-cell must be +1.36 V.

In the list of standard electrode potentials, which is the strongest reducing agent?

• Li

• Li⁺

• F₂

• F^-