What electrode is used as the reference when measuring standard electrode potentials?
Standard hydrogen electrode
All electrode potentials are measured relative to this reference electrode.
What symbol represents the standard electrode potential of a half-cell?
E°
It indicates the electrode potential measured under standard conditions.
Fill in the blank:
Standard electrode potentials are measured at a temperature of _______ K.
298
Standard conditions also include 100 kPa pressure and 1.00 mol dm-3 solutions.
True or False:
Standard electrode potentials are measured with ion concentrations of 1.00 mol dm-3.
True
This ensures all measurements are comparable.
What name is given to the ordered list of standard electrode potentials?
Electrochemical series
It ranks half-cells according to their tendency to be reduced.
True or False:
A more positive E° value indicates a greater tendency to gain electrons.
True
Species with more positive E° values are more easily reduced.
Fill in the blank:
The maximum voltage produced by an electrochemical cell is called the _______.
EMF
EMF stands for electromotive force.
How is the EMF of a cell calculated using standard electrode potentials?
E°cell = E°(reduction) − E°(oxidation)
Alternatively: E°cell = E°(right) − E°(left) from the cell diagram.
True or False:
A positive EMF indicates that the redox reaction is feasible.
True
A positive E°cell suggests the reaction is thermodynamically favourable.
In the conventional cell representation Zn|Zn2+||Cu2+|Cu, which electrode is the negative electrode?
Zinc
Zinc is oxidised and acts as the anode.
Fill in the blank:
In a conventional cell diagram, a double vertical line represents the _______ bridge.
salt
The salt bridge allows ions to move and complete the circuit.
What process occurs at the anode in an electrochemical cell?
Oxidation
The anode is where electrons are released.
What type of device converts chemical energy directly into electrical energy using redox reactions?
Electrochemical cell
These cells allow electron transfer through an external circuit to generate current.
What type of electrochemical cell cannot be recharged once the reactants are used up?
Non-rechargeable cell
These are also called primary cells and operate via irreversible reactions.
True or False:
Fuel cells must be recharged after their reactants are used up.
False
Fuel cells continuously produce electricity as long as fuel and oxidant are supplied.
In a lithium cell, what process occurs at the negative electrode involving lithium atoms?
Oxidation
Lithium atoms lose electrons to form Li+ ions.
Give the half equation for the oxidation of lithium at the negative electrode
Li → Li+ + e-.
Fill in the blank:
In a hydrogen–oxygen fuel cell, hydrogen is _______ at the electrode.
oxidised
Hydrogen loses electrons to form water through reaction with oxygen.
What is the overall product formed in a hydrogen–oxygen fuel cell?
Water
Hydrogen and oxygen combine electrochemically to form water.
True or False:
Fuel cells generate electricity through redox reactions.
True
Oxidation and reduction occur at separate electrodes.
Fill in the blank:
The movement of _______ through the external circuit generates electric current in electrode reactions.
electrons
Electrons flow from the negative electrode to the positive electrode.
What advantage do hydrogen fuel cells offer compared with fossil fuel power sources?
Low emissions
The main product is water, reducing pollution compared with combustion.
Give the half equation for the reduction reaction that occurs at the positive electrode of the lithium cell
Li⁺ + CoO₂ + e⁻ → Li⁺[CoO₂]⁻
Remember Lithium cobalt oxide (LiCoO₂) is the positive electrode in a lithium ion cell
What is the half equation at the negative electrode in an alkaline hydrogen–oxygen fuel cell?
H₂ + 2OH⁻ → 2H₂O + 2e⁻
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3.1.1 Atomic structure50
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3.1.2 Amount of substance47
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3.1.3 Bonding90
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3.1.4 Energetics62
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3.1.5 Kinetics55
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3.1.6 Equilibria & Kc24
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3.1.7 Redox equations17
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3.1.8 Thermodynamics27
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3.1.9 Rate equations24
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3.1.10 Kp12
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3.1.11 Electrode potentials46
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3.1.12 Acids and bases69
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3.2.1 Periodicity22
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3.2.2 Group 2 metals24
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3.2.3 Group 7 (halogens)31
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3.2.4 Period 3 oxides35
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3.2.5 Transition metals95
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3.2.6 Ions in aqueous solution39
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3.3.1 Intro to organic chemistry42
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3.3.2 Alkanes49
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3.3.3 Halogenoalkanes36
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3.3.4 Alkenes36
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3.3.5 Alcohols43
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3.3.6 Organic analysis36
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3.3.7 Optical isomerism12
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3.3.8 Aldehydes & ketones20
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3.3.9 Carboxylic acids & derivatives25
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3.3.10 Aromatic chemistry29
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3.3.11 Amines41
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3.3.12 Polymers24
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3.3.13 Amino acids, proteins, DNA61
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3.3.14 Organic synthesis12
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3.3.15 NMR spectroscopy14
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3.3.16 Chromatography12
