MCQ 91: Relationship Between Current and Conductance
Question: The relationship between current (I), voltage (V), and conductance (G) is described by which formula?
A) I=G⋅V
B) I=V⋅G
C) V=I⋅G
D) V=IG
Answer: A) I=G⋅V
Explanation: The current (I) through a conductor is equal to the product of the conductance (G) and the voltage (V) applied across it.
MCQ 92: Cell Voltage Measurement
Question: When measuring the voltage of a cell, a positive voltage indicates:
A) A non-spontaneous reaction.
B) A spontaneous reaction.
C) No reaction occurring.
D) The presence of an external power source.
Answer: B) A spontaneous reaction.
Explanation: A positive cell voltage indicates that the electrochemical reaction is spontaneous and will proceed without external energy input.
MCQ 93: Nernst Equation Adaptation
Question: The Nernst equation can be adapted to account for temperature changes by incorporating:
A) The van’t Hoff equation
B) The Arrhenius equation
C) Temperature coefficients
D) The modified reaction quotient
Answer: C) Temperature coefficients
Explanation: The Nernst equation can be adjusted by including temperature coefficients to account for how temperature affects the cell potential.
MCQ 94: Oxidation State Changes
Question: In the reaction Zn+Cu2+→Zn2++Cu, which element is oxidized?
A) Zinc
B) Copper
C) Both zinc and copper
D) Neither
Answer: A) Zinc
Explanation: Zinc is oxidized as it loses electrons and changes from elemental zinc (0 oxidation state) to zinc ions (+2 oxidation state).
MCQ 95: Conductance Measurement Units
Question: What is the SI unit for measuring electric current, which also relates to conductance?
A) Ohm
B) Volt
C) Ampere
D) Siemens
Answer: C) Ampere
Explanation: The ampere (A) is the SI unit for electric current, and it is directly related to conductance, as conductance determines how much current flows for a given voltage.
MCQ 96: Electrochemical Cell Types
Question: Which type of electrochemical cell requires an external power source to operate?
A) Galvanic cell
B) Electrolytic cell
C) Fuel cell
D) Concentration cell
Answer: B) Electrolytic cell
Explanation: An electrolytic cell requires an external power source to drive non-spontaneous reactions, while galvanic cells generate electricity from spontaneous reactions.
MCQ 97: Factors Affecting Conductance
Question: Which of the following factors most directly affects the conductance of an electrolyte solution?
A) The color of the solution
B) The presence of solid impurities
C) The concentration of ions
D) The volume of the solution
Answer: C) The concentration of ions
Explanation: The conductance of an electrolyte solution is directly proportional to the concentration of ions present, as more ions facilitate greater current flow.
MCQ 98: Cell Reaction Direction
Question: In a galvanic cell, the direction of electron flow is from:
A) Cathode to anode
B) Anode to cathode
C) Both electrodes simultaneously
D) Depends on the cell type
Answer: B) Anode to cathode
Explanation: In a galvanic cell, electrons flow from the anode (where oxidation occurs) to the cathode (where reduction occurs).
MCQ 99: Cathode Reactions
Question: In an electrochemical cell, the cathode is defined as the electrode where:
A) Reduction occurs
B) Oxidation occurs
C) Current enters the cell
D) Ions are neutralized
Answer: A) Reduction occurs
Explanation: The cathode is the electrode at which reduction takes place, meaning it gains electrons during the electrochemical reaction.
MCQ 100: Energy Conversion in Electrochemical Cells
Question: What type of energy conversion occurs in a galvanic cell?
A) Chemical to mechanical
B) Mechanical to electrical
C) Chemical to electrical
D) Electrical to thermal
Answer: C) Chemical to electrical
Explanation: In a galvanic cell, chemical energy stored in reactants is converted into electrical energy during the spontaneous redox reactions
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