What type of reaction involves the transfer of electrons between substances?
Redox reaction
Redox reactions involve oxidation and reduction occurring together via electron transfer.
What is the loss of electrons from a species called?
Oxidation
Remember the mnemonic OIL RIG: Oxidation Is Loss, Reduction Is Gain.
What is the gain of electrons by a species called?
Reduction
Reduction occurs when a species gains one or more electrons.
True or False:
Oxidising agents donate electrons during a redox reaction.
False
Oxidising agents accept electrons and are themselves reduced.
What name is given to a substance that accepts electrons in a redox reaction?
Oxidising agent
Because it causes another substance to be oxidised.
True or False:
A reducing agent donates electrons to another species.
True
The reducing agent loses electrons and therefore becomes oxidised.
Fill in the blank:
The numerical value assigned to an atom to show electron loss or gain in compounds is its oxidation _______.
state
Oxidation states help track electron transfer in reactions.
What happens to the oxidation state of an element when it is oxidised?
It increases.
Losing electrons makes the oxidation state more positive.
True or False:
Reduction results in a decrease in oxidation state.
True
Gaining electrons lowers the oxidation number.
What type of equation shows either the oxidation or reduction process separately in a redox reaction?
Half-equation
Half-equations show electron transfer clearly.
Fill in the blank:
When combining half-equations to form an overall redox equation, the number of _______ must be equal on both sides.
electrons
Electrons lost in oxidation must equal electrons gained in reduction. They cancel out when the half-equations are combined, ensuring the overall equation is balanced for charge.
In an oxidation half-equation, are electrons on the left or right side?
Right side
If a species is being oxidised it is releasing electrons, and anything released in a chemical equation is written on the right-hand side (products side).
In a reduction half-equation, are electrons on the left or right side?
Left side
Reduction = Gain of electrons (RIG)
So the species is taking in electrons, and anything that is taken in is written on the left-hand side (reactants side)
What is used to balance oxygen atoms in a half-equation?
Water
(H₂O)
What is used to balance hydrogen atoms in a half equation?
Hydrogen ions
(H⁺)
What is used to balance charge in a half-equation?
Electrons
(e⁻)
What is the correct order for balancing half-equations?
- Balance non-O/H atoms
- Balance O with H₂O
- Balance H with H⁺
- Balance charge with e⁻
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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
