What does OIL RIG stand for?

Oxidation Is Loss of electrons, Reduction Is Gain of electrons.

What is a redox reaction?

A reaction in which oxidation and reduction happen at the same time.

What is an oxidising agent?

A substance that takes electrons from another substance and is itself reduced.

What is a reducing agent?

A substance that gives electrons to another substance and is itself oxidised.

In CuO + H₂ → Cu + H₂O, which substance is reduced?

Copper(II) oxide, because it loses oxygen.

Write the half-equation for magnesium forming Mg²⁺.

Mg → Mg²⁺ + 2e⁻ (oxidation)

Write the half-equation for Cu²⁺ ions forming copper.

Cu²⁺ + 2e⁻ → Cu (reduction)

On which side are the electrons in an oxidation half-equation?

On the right-hand side (they are products).

What happens in a displacement reaction?

A more reactive metal displaces a less reactive metal from its compound, and electrons are transferred.

Why is rusting a redox reaction?

Iron gains oxygen and loses electrons, so it is oxidised.

Why is combustion a redox reaction?

The fuel gains oxygen, so it is oxidised.

Oxidation and reductionIB MYP Chemistry: Flashcards

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What is oxidation in terms of oxygen?

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What is oxidation in terms of oxygen?: Gain of oxygen.
What is reduction in terms of oxygen?: Loss of oxygen.
What does OIL RIG stand for?: Oxidation Is Loss of electrons, Reduction Is Gain of electrons.
What is a redox reaction?: A reaction in which oxidation and reduction happen at the same time.
What is an oxidising agent?: A substance that takes electrons from another substance and is itself reduced.
What is a reducing agent?: A substance that gives electrons to another substance and is itself oxidised.
In CuO + H₂ → Cu + H₂O, which substance is reduced?: Copper(II) oxide, because it loses oxygen.
Write the half-equation for magnesium forming Mg²⁺.: Mg → Mg²⁺ + 2e⁻ (oxidation)
Write the half-equation for Cu²⁺ ions forming copper.: Cu²⁺ + 2e⁻ → Cu (reduction)
On which side are the electrons in an oxidation half-equation?: On the right-hand side (they are products).
What happens in a displacement reaction?: A more reactive metal displaces a less reactive metal from its compound, and electrons are transferred.
Why is rusting a redox reaction?: Iron gains oxygen and loses electrons, so it is oxidised.
What is needed for iron to rust?: Both oxygen and water.
Why is combustion a redox reaction?: The fuel gains oxygen, so it is oxidised.

Exam questions on Oxidation and reduction

A student in Athens burns a strip of magnesium ribbon in air. It burns with a bright white flame and leaves a white powder of magnesium oxide, MgO, as shown by the equation 2Mg + O₂ → 2MgO. Magnesium oxide is an ionic compound made of Mg²⁺ ions and O²⁻ ions.
Write the half-equation for magnesium atoms forming Mg²⁺ ions and explain why this is oxidation.2 marks
A teacher heats black copper(II) oxide, CuO, in a stream of hydrogen gas. The black solid turns into a pink-brown solid, copper, and steam is formed: CuO + H₂ → Cu + H₂O.
Explain why this is a redox reaction, in terms of oxygen.2 marks
Students at a school in Manila investigate the conditions needed for iron to rust. They set up three test tubes, each containing a clean iron nail. Tube A has boiled water with a layer of oil on top. Tube B has dry air and a drying agent, calcium chloride. Tube C has tap water and is open to the air. They leave the tubes for one week.
State a hypothesis for this investigation, with a scientific reason.3 marks

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Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).