Reactivity Series Flashcards
Name the elements in order of reactivity
potassium, sodium, lithium, calcium, magnesium, aluminium, (carbon), zinc, iron, (hydrogen), copper, silver and gold
Describe some reactions with water
K, Na and Li:
2X + 2H2O —–> 2XOH + H2
Calcium:
Reacts gently. Grey granules sink but are carried back to the surface again as bubble of hydrogen are formed around them. The mixture becomes water as heat is produced.
Calcium hydroxide is formed, some of it dissolves to give a colourless solution but most is left as a white, insoluble solid.
Magnesium:
No reaction because magnesium becomes coated with insoluble magnesium hydroxide, which prevents water coming into contact with the magnesium.
Describe some reactions with dilute acids
K, Na, Li and Ca:
Too reactive to add safely to acids. Calcium can be used if acid is very dilute.
Magnesium: reacts vigorously and the mixture gets very hot. Hydrogen is produced. Colourless solution is formed.
Aluminium: slow to start but after warming reacts very vigorously. There is a thin but strong later of aluminium oxide on the surface of the aluminium which stops the acid getting to it. On heating the acid removes this layer.
Zinc & Iron: react slowly in cold but rapidly on heating. The vigour of the reactions is less than aluminium. Hydrogen is produced.
Deduce the position of a metal within the reactivity series using displacement reactions
Magnesium + copper oxide –> magnesium oxide + copper
Copper is replaced by magnesium.
Magnesium + zinc oxide —> Magnesium oxide + zince
Heating magnesium with zinc oxide produces zinc metal. Because the zinc is very hot, it immediately burns in air again to form zinc oxide
Carbon + Copper Oxide —> Carbon dioxide + Copper
A black mixture of carbon and copper oxide is heated in a test tube to avoid the air getting at the hot copper produced and turning it back to copper oxide. The carbon dioxide that is also formed escapes as a gas. The mixture glows red hot because of the heat given out during the reaction and you are left with brown copper.
What is oxidation and reduction?
Oxidised: loss of oxygen
Reduction: gain of oxygen
What are meant by the terms redox, oxidising agent, reducing agent?
Redox - reaction in which reduction and oxidation takes place
Oxidising agent: substance which reduces something else
Reducing agent: substance which oxidises something else
Describe the conditions under which iron rusts
Oxygen and water
Describe how the rusting of iron may be prevented by grease, oil, paint, plastic and galvanising
They prevent water and oxygen from making contact with iron but once the coating is broken, the iron will rust.
Describe the sacrificial protection of iron
Zinc is more reactive than iron so when blocks of zinc are bolted to iron, it is oxidised instead of the iron.
