4 1 reactivity of metals

Oxidation is a reaction in which oxygen is added to an element or a compound.

Reduction is a reaction in which oxygen is removed from an element or a compound.

True. In the reaction 2Cu + O2 → 2CuO, copper has been oxidised.

False. In the reaction of iron with oxygen to form iron(III) oxide, iron has been oxidised.

The product when zinc reacts with oxygen is zinc oxide, ZnO.

The word equation for the oxidation of magnesium is: magnesium + oxygen → magnesium oxide

The general equation for a metal reacting with an acid is: metal + acid → salt + hydrogen

True. Only metals above hydrogen in the reactivity series will react with dilute acids.

The equation for the reaction of calcium with water is: Ca (s) + 2H2O (l) → Ca(OH)2 (aq) + H2 (g)

False. Copper is less reactive than hydrogen.

False. Magnesium reacts very slowly with cold water.

False. Potassium is more reactive than sodium.

True. Potassium reacts violently with water and acid.

A metal that is above carbon in the reactivity series is:

A metal that is below hydrogen in the reactivity series is:

Zinc is more reactive than iron.

Aluminium is more reactive than zinc.

One mnemonic to remember the reactivity series is: “Please send lions, cats, monkeys and cute zebras into hot countries signed Gordon” Potassium, sodium, lithium, calcium, magnesium, carbon, zinc, iron, hydrogen, copper, silver and gold

False. The most reactive metal is found at the top of the reactivity series.

Carbon and hydrogen are usually included in the reactivity series because they are useful in extracting metals from their oxides by reduction processes.

False. Only metals above hydrogen in the reactivity series react with cold water.

The general equation for a metal reacting with water is: metal + water → metal hydroxide + hydrogen

Displacement occurs when a more reactive substance takes the place of a less reactive substance.

The products formed when iron reacts with silver nitrate solution are iron(II) nitrate and silver.

Aluminium does not readily react with water and acids because it has a protective layer of aluminium oxide.

True. Magnesium can displace copper from copper sulfate solution, because it is more reactive.

Metals above carbon in the reactivity series are extracted by electrolysis.

False. The most reactive metals are at the top of the reactivity series.

The position of the metal on the reactivity series determines the extraction method.

Metals that must be extracted by electrolysis are higher up the reactivity series (above carbon) and include aluminum, sodium, potassium, calcium, lithium and magnesium.

False. Iron is extracted by reduction / in the blast furnace.

Metals below carbon in the reactivity series are extracted by heating / reduction with carbon.

False. Metals higher up are less resistant to oxidation than the metals placed lower down which are more resistant to oxidation.

When extracted by heating with carbon, the metal undergoes a reduction reaction.

False. Aluminium is extracted using electrolysis.

A metal ore is a rock that contains enough of a metal to make it worthwhile extracting.

The general equation for the reduction of a metal oxide by carbon is: metal oxide + carbon → metal + carbon dioxide

False. The extraction of metals by heating with carbon is cheaper than electrolysis because carbon is inexpensive and can also be a source of heat.

Oxidation is the loss of electrons.

The balanced symbol equation is: Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)

Reduction is the gain of electrons.

A redox reaction is one where oxidation and reduction occur simultaneously.

True. In the reaction, magnesium has been oxidised as it has lost electrons.

The species which has been reduced is copper as it has gained electrons.

The half equation for the oxidation of zinc atoms is: Zn ⟶ Zn2+ + 2e-

A half equation for the reduction of copper ions is: Cu2+ + 2e- ⟶ Cu

Spectator ions are ions that appear unchanged on both sides of a chemical equation and do not participate in the reaction.

OIL RIG stands for Oxidation Is Loss, Reduction Is Gain of electrons.

The half equation for the reduction of lead(II) ions is: Pb2+ + 2e- → Pb

The half equation for the oxidation of bromide ions is: 2Br- → Br2 + 2e-