Unit 1 - Oxidising & Reducing Agents Flashcards
What is oxidation?
Loss of electrons
What is reduction?
Gain of electrons
What is redox?
Reduction and Oxidation happening simultaneously
What type of reaction is Cu(s) → Cu²⁺(aq) + 2e⁻?
Oxidation
What type of reaction is 2Cl⁻(aq)→ Cl₂(g) + 2e⁻?
Reduction
What type of reaction is MnO₄⁻(aq) + 8H⁺(aq) + 5e⁻ → Mn²⁺(aq) + H₂O?
Reduction
What type of reaction is Fe²⁺(aq) → Fe³⁺(aq) + e⁻?
Reduction
What is a spectator ion?
One which does not take part in the reaction. It is in the same state at the start and end of the reaction.
Combine to form a redox reaction: 2I⁻(aq) → I₂(s) + 2e⁻ and Fe³⁺(aq) + e⁻ → Fe²⁺.
2I⁻(aq) + 2Fe³⁺(aq) → I₂(s) + 2Fe²⁺(aq)
Name the reaction which happens in batteries and cells.
Redox
What is an oxidising agent?
- An oxidising agent is a substance that accepts electrons.
- It causes other substances to be oxidised.
- It is reduced itself.
What is a reducing agent?
- A reducing agent is a substance that donates electrons.
- It causes other substances to be reduced.
- It is oxidised itself.
Identify the spectator ion(s) in the reaction Zn(s) + Cu²⁺(aq) + SO₄²⁻(aq) → Zn²⁺(aq) + SO₄²⁻(aq) + Cu(s).
- sulfate ions
SO₄²⁻(aq)
Identify the oxidising agent in the reaction Zn(s) + Cu²⁺(aq) + SO₄²⁻(aq) → Zn²⁺(aq) + SO₄²⁻(aq) + Cu(s).
Copper ions
Cu²⁺(aq)
Identify the reducing agent in the reaction Zn(s) + Cu²⁺(aq) + SO₄²⁻(aq) → Zn²⁺(aq) + SO₄²⁻(aq) + Cu(s).
Zinc
Zn(s)
What type of substances tend to be reducing agents?
- Elements with low electronegativities tend to form ions by losing electrons and so act as reducing agents.
- In the periodic table, the strongest reducing agents are in group 1.
- In the electrochemical series, the strongest reducing agents are found at the top right.
What type of substances tend to be oxidising agents?
- Elements with high electronegativities tend to form ions by gaining electrons and so act as oxidising agents.
- In the periodic table, the strongest oxidising agents are in group 7.
- In the electrochemical series, the strongest reducing agents are found at the bottom left.
Is hydrogen peroxide an oxidising agent or a reducing agent?
Reducing agent
Is the permanganate ion an oxidising agent or a reducing agent?
Oxidising agent
Is the dichromate ion an oxidising agent or a reducing agent?
Oxidising agent
Is carbon monoxide an oxidising agent or a reducing agent?
Reducing agent
How is potassium permanganate commonly used as an oxidising agent?
Potassium permanganate can be used in fish tanks and ponds to kill parasites, bacteria and fungal infections in fish.
Potassium permanganate can be used as an oxidising agent for rocket fuel.
How is sodium chlorate commonly used as an oxidising agent?
Sodium chlorate (Na⁺ClO₃⁻) is a powerful oxidiser used as a weedkiller and can be used to make explosives.
How is chlorine commonly used as an oxidising agent?
- Chlorine is added to the water supply and to swimming pools to kill microorganisms.
- Bleach
How are hypochlorite ions and hydrogen peroxide commonly used as oxidising agents?
- Bleach
Where are oxidising agents found in the electrochemical series?
- The strongest oxidising agents are at the bottom of the left-hand column of the electrochemical series.
Where are reducing agents found in the electrochemical series?
The strongest reducing agents are at the top of the right-hand column of the electrochemical series.
What are the steps for balancing an ion electron equation?
- Balance elements other than oxygen and hydrogen.
- Balance oxygen by adding water.
- Balance hydrogen by adding H⁺ ions.
- Balance the charge by adding electrons.
Balance the following: IO₃⁻(aq) → I₂(aq).
2 IO₃⁻(aq) + 12 H⁺(aq) + 10 e⁻ → I₂(aq) + 6 H₂O(l)
Balance the following: ClO¯(aq) → Cl¯(aq).
ClO¯ (aq) + 2 H⁺(aq) + 2 e¯ → Cl¯ (aq) + H₂O(l)
