Chemistry Test Electrochemistry 2 ā Questions and Answers
Question 1: What is electrolysis?
- Spontaneous redox reaction producing electricity
- Using electrical energy to drive a non-spontaneous reaction (Correct answer)
- Measuring electrode potential
- Converting chemical energy to heat
Correct answer: Using electrical energy to drive a non-spontaneous reaction
Electrolysis uses electrical energy to drive a non-spontaneous chemical reaction, the reverse of what occurs in a galvanic cell.
Question 2: In an electrolytic cell, which electrode is connected to the positive terminal of the power source?
- Anode (Correct answer)
- Cathode
- Salt bridge
- Reference electrode
Correct answer: Anode
The anode in an electrolytic cell is connected to the positive terminal, attracting anions and where oxidation occurs.
Question 3: How many grams of silver (Ag, molar mass = 108 g/mol) are deposited by 96,485 coulombs during electrolysis of AgNOā?
- 54 g
- 108 g (Correct answer)
- 216 g
- 27 g
Correct answer: 108 g
One mole of electrons (96,485 C) reduces one mole of Agāŗ (since Agāŗ + eā» ā Ag), depositing 108 g of silver.
Question 4: Which type of cell converts chemical energy directly into electrical energy?
- Electrolytic cell
- Galvanic (voltaic) cell (Correct answer)
- Fuel cell electrolysis unit
- Concentration cell at equilibrium
Correct answer: Galvanic (voltaic) cell
A galvanic (voltaic) cell uses spontaneous redox reactions to convert chemical energy directly into electrical energy.
Question 5: What does a positive standard cell potential (EĀ°cell > 0) indicate?
- Non-spontaneous reaction
- Spontaneous reaction (Correct answer)
- Reaction at equilibrium
- Endothermic reaction
Correct answer: Spontaneous reaction
A positive EĀ°cell means ĪGĀ° is negative, indicating the redox reaction is spontaneous under standard conditions.
Question 6: In a concentration cell, current flows because of a difference in what?
- Temperature
- Electrode material
- Ion concentration between two half-cells (Correct answer)
- Salt bridge composition
Correct answer: Ion concentration between two half-cells
A concentration cell generates voltage from the difference in ion concentration between two identical electrodes immersed in solutions of different concentrations.
Chemistry Test Electrochemistry 2
What is electrolysis?