1. The half-reaction that represents oxidation is:
Answer:
Explanation:
Oxidation involves the loss of electrons. Here, Zn loses 2 electrons.
2. The electrode at which reduction occurs is called:
Answer:
Explanation:
Reduction always occurs at the cathode in both electrolytic and galvanic cells.
3. In a galvanic cell, the electron flow is from:
Answer:
Explanation:
In a galvanic cell, the anode is the site of oxidation and releases electrons which flow to the cathode.
4. Which of the following is NOT an application of electrolysis?
Answer:
Explanation:
Burning a candle is a physical process and does not involve electrolysis.
5. The unit of electrical resistance is:
Answer:
Explanation:
The unit of resistance is Ohm, represented by the symbol Ω.
6. Faraday's second law of electrolysis relates to:
Answer:
Explanation:
Faraday's second law states that the amounts of substances deposited on electrodes during electrolysis are proportional to their chemical equivalents or valencies.
7. A solution with high concentration of ions will have:
Answer:
Explanation:
A higher concentration of ions enhances the solution's ability to conduct electricity.
8. The relationship between Gibbs free energy (ΔG) and cell potential (E) is given by:
Answer:
Explanation:
Gibbs free energy change and cell potential are related by the equation ΔG = -nFE where n is the number of moles of electrons and F is the Faraday constant.
9. The standard electrode potential for hydrogen is:
Answer:
Explanation:
By convention, the standard electrode potential for hydrogen is taken as 0 V.
10. The process of preventing the corrosion of metals by attaching a more reactive metal to it is called:
Answer:
Explanation:
The more reactive metal gets corroded, thus protecting the main metal from corrosion.
11. Which cell will NOT be recharged after being used?
Answer:
Explanation:
Primary cells are designed for one-time use and cannot be recharged. Secondary cells, on the other hand, are rechargeable.
12. In a concentration cell, if the concentration of the electrolyte in one half-cell is increased, the cell potential will:
Answer:
Explanation:
In concentration cells, an increase in the concentration difference between the two half-cells will lead to an increased cell potential.
13. Which of the following reactions at an electrode is an example of a reduction process?
Answer:
Explanation:
The addition of an electron to Ag+ ions represents a reduction process.
14. The oxidation number of chlorine in ClO3- ion is:
Answer:
Explanation:
Let x be the oxidation number of Cl. Considering the oxidation number of oxygen as -2, we have: x + 3(-2) = -1. Solving for x gives x = +5.
15. The molar conductivity of a solution at infinite dilution is the sum of the molar conductivities of its:
Answer:
Explanation:
The total molar conductivity at infinite dilution is the sum of the molar conductivities of both its cations and anions.
16. Which of the following is NOT an example of a redox reaction?
Answer:
Explanation:
There is no change in oxidation states for any of the elements involved in the reaction between NaOH and HCl.
17. Electrolysis of water produces:
Answer:
Explanation:
Water undergoes electrolysis to produce oxygen at the anode (oxidation) and hydrogen at the cathode (reduction).
18. In a salt bridge, the commonly used inert electrolyte is:
Answer:
Explanation:
K2SO4 remains un-ionized and thus provides a pathway for the flow of ions without participating in the cell reaction.
19. Which of the following metals can displace hydrogen from dilute acids?
Answer:
Explanation:
Zinc is more reactive than hydrogen and can displace it from dilute acids. Cu, Ag, and Au are less reactive than hydrogen in this regard.
20. The Nernst equation relates:
Answer:
Explanation:
The Nernst equation relates cell potential to temperature, concentration, and the number of electrons transferred in the redox reaction.