2 f) reactivity series

Question 1

2.29 understand that metals can be arranged in a reactivity series based on the reactions of the metals and their compounds: potassium, sodium, lithium, calcium, magnesium, aluminium, zinc, iron, copper, silver and gold

Answer 1

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Question 2

2.30 describe how reactions with water and dilute acids can be used to deduce the following order of reactivity: potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper

Answer 2

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Potassium, sodium, lithium, calcium react with water and acids.

Magnesium, aluminium, zinc ,iron ,tin, lead can react, Copper can’t react with any of them.

The more the vigorous the element is in the reaction, the more reactive the element is and the more things they can react with.

Question 3

2.31 deduce the position of a metal within the reactivity series using displacement reactions between metals and their oxides, and between metals and their salts in aqueous solutions

Answer 3

If metal is reactive than the metal in metal oxide, the metal will be displaced and reaction will occur in water. If metal is less reactive than the metal in metal oxide, no reaction will occur.

In this way we can work out their position in reactivity series.

Question 4

2.32 understand oxidation and reduction as the addition and removal of oxygen respectively

Answer 4

Oxidation: Oxidation means addition of oxygen to an element Reduction: Reduction means removal of oxygen from an element

Question 5

2.33 understand the terms redox, oxidising agent, reducing agent

Answer 5

Redox reaction: If in a reaction, both oxidation and reduction take place, it is called redox reaction.

Oxidizing agent: Oxidising agent is a substance that oxidizes others but reduce itself from the reaction. Reducing agent: Reducing agent is a substance that reduces others but oxides itself from the reaction.

Oxidising agent:
1)Bromine
2) chlorine
3) concentrate sulphuric acid
4) nitric acid
5) Oxygen
6) potassium manganate (VII)
7) Potassium dichromate
8) Hydrogen Peroxide
Reducing agent:
1) carbon
2) carbon monoxide
3) hydrogen
4) hydrogen sulphide
5) metals
6) potassium iodide
7) sulphur dioxide
8) ammonia

Question 6

2.34 describe the conditions under which iron rusts

Answer 6

· Both air and water are needed for rusting to occur

· The presence of sodium chloride increases the speed of rusting.

Question 7

2.35 describe how the rusting of iron may be prevented by grease, oil, paint, plastic and galvanising

Answer 7

Grease, oil, paint and plastic prevent air and or water from coming into contact with iron. This means the reaction that

rusts iron can’t occur.

Galvanizing is coating in zinc. This Zinc react in the air to form ZnCO3 which prevents air and or water from coming into contact with the iron.

Question 8

2.36- understand the sacrificial protection of iron in terms of the reactivity series.

Answer 8

Magnesium or zinc are used as sacrificial protection of iron. If you keep them beside or attach them to iron, magnesium or zinc will corrode instead of iron. Because they are more reactive than iron. As long as magnesium or zinc is present, iron will not rust.