Free Electrochemistry MCQs with Answers
696 Electrochemistry MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Electrochemistry describes electron transfer through oxidation and reduction, identifies oxidizing and reducing agents, and applies oxidation numbers to balance redox equations. It also covers electrode potential and the standard hydrogen electrode, which provides the reference for comparing the reduction tendencies of other electrodes.
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Read the Electrochemistry notesFree MDCAT chapter notes with key terms696 questions · page 27 of 35
- A. 1 atm pressure
- B. 1M H+ solution
- C. 298 K temperature
- D. All of these
Explanation: Conditions for SHE:i) Pt electrode coated with finely divided Pt blackii) T = 25°C = 298kiii) 1M = H+ ionsiv) P = 1 atm
Correct answer: All of these- A. pH scale
- B. Redox scale
- C. Hydrogen scale
- D. Arrhenius scale
Explanation: ECS shows Eeredvalue in ascending order and Eered is measured by comparing with SHE i.e. H-scale.
Correct answer: Hydrogen scale- A. +2
- B. +4
- C. +6
- D. +8
Explanation: The oxidation number of sulfur in sodium sulfate (Na2SO4) is +6. Oxidation state is a number assigned to an atom in a chemical compound…
Correct answer: +6- A. It keeps both solutions seperate
- B. It maintains electrical neutrality in the cell
- C. It maintains flow of electric current through external circuit
- D. The positive charge around cathode electrode would prevent the flow of electrons from it
Explanation: The salt bridge is a type of electrolyte that contains ions that can move freely.
Correct answer: The positive charge around cathode electrode would prevent the flow of electrons from it- A. SHE
- B. CI2
- C. F2
- D. Cu
Explanation: The standard electrode potential of Zinc is measured by coupling it with the standard hydrogen electrode (SHE).
Correct answer: SHE- A. Strongest reducing agent
- B. Strongest oxidizing agent
- C. Weakest oxidizing agent
- D. Weakest reducing agent
Explanation: Lithium having the largest negative value of electrode potential, is the strongest reducing agent.
Correct answer: Strongest oxidizing agent- A. <Cu
- B. >Cu
- C. <SO4-2
- D. >SO4-2
Explanation: If left in the solution for a longer period of time, The zinc will gradually decay due to oxidation to zinc ions.
Correct answer: >Cu- A. I only
- B. II only
- C. III and IV only
- D. l ,ll,lll and lV
Explanation: The anode is usually the positive sideA cathode is a negative side. It acts as an electron donor. It acts as an electron acceptor.
Correct answer: l ,ll,lll and lV- A. Negative
- B. Positive
- C. Zero
- D. Unity
Explanation: If a certain atom gains electrons, its oxidation number will decrease. In other words, the oxidation number of the atom becomes more…
Correct answer: Negative- A. A negative charge
- B. A net positive charge
- C. Neutral
- D. None of these
Explanation: The correct answer is (a) A Negative Charge, as explained above.
Correct answer: A negative charge- A. Buffer
- B. Salt bridge
- C. Electrical conductor
- D. All of these
Explanation: Pt is a noble metal that is very stable and resistant to corrosion. Because of its stability, like Au, it is often used to make jewelry.
Correct answer: Electrical conductor- A. Standard
- B. Zero Volts
- C. Unity
- D. Both A and B
Explanation: A Standard Hydrogen Electrode (SHE) is an electrode that scientists use for reference on all half-cell potential reactions.
Correct answer: Both A and B- A. Copper sulphate
- B. Copper chloride
- C. Zinc chloride
- D. Zinc sulphate
Explanation: One half -cell in a voltaic cell is constructed from a silver wire dipped in silver nitrate solution of unknown concentration.
Correct answer: Zinc sulphate- A. Graphite
- B. Copper
- C. Iron
- D. Silver
Explanation: The Downs cell uses carbon and an iron cathode. The electrolyte is sodium chloride that has been heated to the liquid state.
Correct answer: Graphite- A. Cathode to anode
- B. Anode to cathode
- C. Right to left
- D. None of these
Explanation: Electrons flow from The anode to the cathode through an external wire. A common galvanic cell is the Daniell cell
Correct answer: Anode to cathode- A. 256
- B. 384
- C. 250
- D. 192
Explanation: The sequence 8, 16, 32, 64, 128, ? follows a pattern where each term is the result of multiplying the previous term by 2:8 × 2 = 1616 × 2…
Correct answer: 256- A. 2
- B. 3
- C. 6
- D. 9
Explanation: The correct answer is 9. The family consists of:1 mother1 unmarried daughter3 daughters-in-law (one for each married son)4 grand-daughters…
Correct answer: 9- A. A. If statement I is the cause and statement II is its effect;
- B. B. If statement II is the cause and statement I is its effect;
- C. C. If both the statements I and II are independent causes;
- D. D. If both the statements I and II are effects of independent causes;
- E. E. If both the statements I and II are effects of some common cause;
Explanation: Statement I indicates an increase in police patrolling in the evenings, which directly addresses the issue of petty crimes.
Correct answer: A. If statement I is the cause and statement II is its effect;- A. If only I follows
- B. If only II follows
- C. If either I or II follows
- D. If neither I nor II follows
- E. If both I and II follow
Explanation: The correct answer is Option E: If both I and II followCourse of Action I suggests that the state government should proactively purchase…
Correct answer: If both I and II follow- A. S
- B. SO2
- C. H2SO3
- D. H2S
Explanation: H2S is correct because it is the product formed when Hl reduces H2SO4 due to the reduction of sulfur in sulfuric acid.
Correct answer: H2S