MCQ 51: Effect of Concentration on Cell Potential
Question: If the concentration of reactants in a galvanic cell increases, what happens to the cell potential?
A) It decreases
B) It remains the same
C) It increases
D) It becomes zero
Answer: C) It increases
Explanation: According to the Nernst equation, increasing the concentration of reactants shifts the equilibrium toward the products, increasing the cell potential.
MCQ 52: Half-Cell Definitions
Question: A half-cell consists of:
A) Only an anode
B) Only a cathode
C) An electrode and its corresponding electrolyte
D) Only a salt bridge
Answer: C) An electrode and its corresponding electrolyte
Explanation: A half-cell is made up of an electrode in contact with an electrolyte solution that contains ions participating in the electrochemical reaction.
MCQ 53: Conductance and Temperature
Question: What is the general effect of temperature on the conductance of a solution?
A) Decreases with increasing temperature
B) Increases with increasing temperature
C) No significant effect
D) Only affects solid conductors
Answer: B) Increases with increasing temperature
Explanation: Increasing the temperature typically enhances the mobility of ions in a solution, thereby increasing its conductance.
MCQ 54: Ion Selectivity
Question: Which ion is most commonly used in the reference electrode for measuring pH?
A) Sodium ion (Na⁺)
B) Potassium ion (K⁺)
C) Hydrogen ion (H⁺)
D) Silver ion (Ag⁺)
Answer: C) Hydrogen ion (H⁺)
Explanation: The hydrogen ion concentration is critical for pH measurement, making it essential for reference electrodes used in pH meters.
MCQ 55: Discharge of Ions
Question: During electrolysis, which ion is likely to discharge at the cathode in an aqueous solution?
A) Na⁺
B) H⁺
C) Cl⁻
D) OH⁻
Answer: B) H⁺
Explanation: In aqueous solutions, hydrogen ions (H⁺) are typically discharged at the cathode due to their higher reduction potential compared to other cations like Na⁺.
MCQ 56: Standard Electrode Potentials
Question: The standard electrode potential is a measure of:
A) The ability of an electrode to conduct electricity
B) The tendency of a species to be reduced
C) The concentration of ions in solution
D) The temperature of the electrolyte
Answer: B) The tendency of a species to be reduced
Explanation: Standard electrode potentials indicate how easily a species can gain electrons and be reduced, providing insight into its reactivity.
MCQ 57: Corrosion Prevention
Question: Which method is commonly used to prevent corrosion in metals?
A) Painting
B) Galvanization
C) Cathodic protection
D) All of the above
Answer: D) All of the above
Explanation: Various methods such as painting, galvanization, and cathodic protection are used to prevent corrosion by isolating the metal from the environment or by providing a sacrificial anode.
MCQ 58: Electrolyte Function
Question: In an electrolytic cell, the electrolyte serves primarily to:
A) Provide thermal energy
B) Allow ion migration
C) Act as a barrier
D) Maintain constant temperature
Answer: B) Allow ion migration
Explanation: The electrolyte provides the medium for ion migration between the anode and cathode, enabling the electrochemical reaction to occur.
MCQ 59: Nernst Equation Factors
Question: In the Nernst equation, what does a negative cell potential indicate?
A) The reaction is spontaneous.
B) The reaction is non-spontaneous.
C) The system is at equilibrium.
D) The temperature is too low.
Answer: B) The reaction is non-spontaneous.
Explanation: A negative cell potential suggests that the electrochemical reaction is not spontaneous under the given conditions and requires an external energy source to proceed.
MCQ 60: Voltaic Cell
Question: A voltaic cell generates electricity from:
A) Heat
B) Light
C) Spontaneous chemical reactions
D) External electrical sources
Answer: C) Spontaneous chemical reactions
Explanation: A voltaic cell, also known as a galvanic cell, converts the energy released from spontaneous chemical reactions into electrical energy.
Leave a comment