Quiz

QUIZ

1. What does the ammeter measure in units?

a. Charge b. Amperes c. Joules d. Coulombs

Answer: b. The ammeter measures amperes or the electrical charge that passes through the system per second.

2. What are the units for Coulombs?

a. Joules per second b. Amp-seconds c. Volts d. Ohms

Answer: b. The units for coulombs are amp-seconds, which can be calculated using an ammeter.

3. In a reaction where zinc metal plus bromine gas goes to zinc 2+ ions and

Bromine 2- ions, what is the reductant in this situation?

a. Zinc b. Bromine gas c. Zinc ions d. Bromine ions

Answer: a. The zinc is the reductant because it reduces something else, getting oxidized at the same time.

4. In a reaction where Zinc metal plus iodine goes to zinc (II) ions plus 2 iodide ions, what is the oxidant?

a. Zinc b. Iodine c. Zinc ions d. Iodide ions

Answer: b. The iodine is the oxidant in the reaction because it gets reduced but oxidizes something else.

5. What statement is the same for both a galvanic cell and an electrolytic cell?

a. It involves the spontaneous passage of electrons through a wire. b. It involves separate reduction and oxidation reactions. c. It involves a spontaneous redox reaction. d. Electricity is generated by the cell.

Answer: b. The only thing that is true for both the galvanic cell and an electrolytic cell is that they both involve separate oxidation and reduction reactions. The rest of the statements cannot be applied to both types of cells.

6. What is the main difference between a galvanic cell and an electrolytic cell?

a. The electrolytic cell involves electrolytes and the galvanic cell does not. b. The galvanic cell involves metals and electrolytic cells do not. c. The galvanic cell involves redox reactions and electrolytic cells do not. d. The galvanic cell generates electricity, while the electrolytic cells use up electricity.

Answer: d. The main difference is that the galvanic cell generates electricity while the electrolytic cell uses up electricity. They both involve redox reactions and many involve metals and metal ions.

7. What term does not equate with the term “galvanic cell”?

a. Electric cell b. Electrolytic cell c. Voltaic cell d. Redox cell

Answer: b. The electrolytic cell is completely different from the galvanic cell. The other terms, “electric cell”, “redox cell”, and “voltaic cell” are the same thing as the galvanic cell.

8. What would be the least appropriate ion in a salt bridge in a voltaic cell?

a. K+ b. Na+ c. NO3d. Zn2+

Answer: d. The salt ions in the salt bridge must not precipitate out of solution and must not be able to be oxidized or reduced by themselves. Zinc is reducible so it would not be used easily in a voltaic cell.

9. What is the junction potential in an electrical cell?

a. It is the electrical resistance in the electrical wire. b. It is the potential difference between the two beakers in a cell. c. It is the resistance to the flow of charge at the barrier or the “salt bridge”. d. It is the difference in charge from the cathode to the anode.

Answer: c. The junction potential is the resistance to the flow of charge at the barrier or the salt bridge between the beakers.

10. According to Faraday’s law, under what circumstances would the amount of a metal gained at an electrode in an electric cell not be equal to the amount of metal lost at the other electrode?

a. When the concentrations of the electrolytes are different in each half of the cell b. When the charge on one atom in the electrode does not equal the charge on the other atom’s electrode. c. When the molar mass of one is greater than the molar mass of the other. d. It will never be an unequal mass according to this law.

Answer: b. When the charge on one atom is not equal to the charge on the other atom, the amount of metal would not be the same. The law states that the amount of substance made at each electrode in an electrochemical cell is directly proportional to the quantity of charge that flows through the cell. The law will be accurate if the stoichiometry of the equation is taken into account.