Redox Reactions

Question 1

What is a redox reaction?

Answer 1

A reaction where both oxidation and reduction occur.

Question 2

What is an example of a redox reaction and the word equation?

Answer 2

• Rusting

- Iron + water + oxygen —> hydrated iron (III) oxide

Question 3

What is the process of galvanising?

Answer 3

• Covers iron with zinc
• Thin layer prevents water and oxygen from reaching the surface of the iron
• If it is scratched it acts as a sacrificial metal because it is more reactive

Question 4

What is oxidation and reduction?

Answer 4

• Oxidation: the loss of electrons. An oxidising agent takes electrons away from a substance.
• Reduction: the gain of electrons. A reducing agent gives away electrons.

Question 5

What happens during rusting in terms of oxidation and reduction?

Answer 5

• The iron is oxidised by the oxygen and it loses 2 electrons
• The oxygen is reduced by the iron and gains 2 electrons
• Fe —> Fe^2+ + 2e^-

Question 6

What is the equation of an iron ion being forced from one type to another?

Answer 6

• Fe^2+ —> Fe^3+ + e^-

Question 7

What is a displacement reaction?

Answer 7

When a more reactive metal swaps places (displaces) with a less reactive metal in a compound.

Question 8

What is the order of reactivity from most reactive to least reactive?

Answer 8

• Magnesium
• Zinc
• Iron
• Tin

Question 9

How does a displacement reaction work?

Answer 9

• All metals react by losing electrons and turning into ions (oxidation)
• The electrons are forced onto the ions of the less reactive metal
• This turns the ion back into a metal