Q1. What is a Galvanic Cell?
a) A device that converts chemical energy into electrical energy
b) A device that converts electrical energy into chemical energy
c) A device that generates heat energy from chemical reactions
d) A device that generates light energy from chemical reactions
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Correct Answer: a) A device that converts chemical energy into electrical energy
Explanation: A Galvanic Cell, also known as a voltaic cell, is an electrochemical cell that generates electrical energy from spontaneous chemical reactions. It consists of two different metal electrodes immersed in an electrolyte solution. The chemical reactions occurring at the electrodes produce a flow of electrons, creating an electric current. This current can be harnessed to power various devices. Galvanic cells are widely used in batteries to provide portable electrical energy for numerous applications.
Q2. In a Galvanic Cell, which electrode undergoes oxidation?
a) Anode
b) Cathode
c) Both electrodes undergo oxidation
d) None of the above
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Correct Answer: a) Anode
Explanation: In a Galvanic Cell, oxidation occurs at the anode. During oxidation, the electrode loses electrons and undergoes a chemical change, releasing ions into the electrolyte solution. The electrons produced by this reaction flow through the external circuit to the cathode, generating an electric current. Meanwhile, reduction occurs at the cathode, where the electrons are accepted by ions from the electrolyte, leading to the formation of new substances.
Q3. Which of the following is not a component of a Galvanic Cell?
a) Anode
b) Cathode
c) Salt bridge
d) Filament
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Correct Answer: d) Filament
Explanation: A filament is not a component of a Galvanic Cell. The essential components of a Galvanic Cell include the anode, cathode, and a salt bridge. The anode is where oxidation occurs, the cathode is where reduction occurs, and the salt bridge maintains electrical neutrality by allowing ions to flow between the half-cells, completing the circuit without allowing the mixing of solutions.
Q4. What is the function of a salt bridge in a Galvanic Cell?
a) It completes the circuit
b) It prevents the mixing of electrolytes
c) It allows the flow of electrons
d) It increases the voltage output
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Correct Answer: b) It prevents the mixing of electrolytes
Explanation: A salt bridge in a Galvanic Cell serves to prevent the mixing of electrolytes in the half-cells while allowing the flow of ions to maintain electrical neutrality. Without a salt bridge, charge separation would build up, inhibiting the cell’s operation. It does not contribute to completing the circuit or increasing the voltage output but is crucial for the proper functioning of the cell by maintaining ionic balance.
Q5. What drives the flow of electrons in a Galvanic Cell?
a) Chemical reactions at the electrodes
b) Temperature difference between the electrodes
c) Pressure difference between the electrodes
d) Light energy incident on the electrodes
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Correct Answer: a) Chemical reactions at the electrodes
Explanation: The flow of electrons in a Galvanic Cell is driven by the chemical reactions occurring at the electrodes. Oxidation at the anode releases electrons, while reduction at the cathode accepts these electrons. This flow of electrons through the external circuit generates an electric current, which can be utilized to power various devices. Temperature, pressure, and light energy do not directly drive electron flow in a Galvanic Cell.
Q6. What is the role of electrolyte in a Galvanic Cell?
a) It provides electrons
b) It conducts electricity
c) It catalyzes chemical reactions
d) It regulates temperature
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Correct Answer: b) It conducts electricity
Explanation: The electrolyte in a Galvanic Cell serves as a medium for the flow of ions between the electrodes. It facilitates the completion of the circuit by allowing the movement of charged particles, thus conducting electricity. While it does participate in the overall electrochemical reactions, its primary role lies in enabling the transfer of charge rather than providing electrons, catalyzing reactions, or regulating temperature.
Q7. Which metal is commonly used as the anode in a Galvanic Cell?
a) Gold
b) Zinc
c) Copper
d) Silver
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Correct Answer: b) Zinc
Explanation: Zinc is commonly used as the anode in Galvanic Cells due to its relatively high reactivity and favorable electrochemical properties. During the cell’s operation, zinc undergoes oxidation, losing electrons to the electrolyte solution. This process allows zinc to serve as a source of electrons, contributing to the generation of electrical energy in the cell. Other metals like copper, gold, and silver are less commonly used as anodes due to their lower reactivity.
Q8. Which of the following statements about Galvanic Cells is false?
a) They produce electrical energy from chemical reactions
b) Anode undergoes reduction
c) Cathode undergoes oxidation
d) They consist of two different metal electrodes
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Correct Answer: b) Anode undergoes reduction
Explanation: The statement “Anode undergoes reduction” is false. In a Galvanic Cell, the anode undergoes oxidation, not reduction. Oxidation occurs at the anode, where the electrode loses electrons, while reduction occurs at the cathode, where the electrode gains electrons. This process generates an electric current that flows from the anode to the cathode through the external circuit.
Q9. Which law governs the operation of Galvanic Cells?
a) Ohm’s Law
b) Faraday’s Law
c) Newton’s Law of Motion
d) Boyle’s Law
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Correct Answer: b) Faraday’s Law
Explanation: Faraday’s Law governs the operation of Galvanic Cells. It describes the relationship between the amount of substance transformed at an electrode during an electrochemical reaction and the quantity of electricity passed through the cell. This law is essential for understanding the stoichiometry of electrochemical reactions and calculating the efficiency of Galvanic Cells in practical applications.
Q10. What is the standard unit of electromotive force (EMF) in a Galvanic Cell?
a) Joule
b) Volt
c) Ampere
d) Watt
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Correct Answer: b) Volt
Explanation: The standard unit of electromotive force (EMF) in a Galvanic Cell is the volt. EMF represents the maximum potential difference between the two electrodes of the cell when no current is flowing. It is a measure of the cell’s ability to drive electrical current through an external circuit. The volt is named after the Italian physicist Alessandro Volta, who pioneered the study of Galvanic Cells in the late 18th century.