Metals

Question 1

What is the equation for a reaction between a metal and acid?

Answer 1

metal + acid ➡ salt + hydrogen
eg. magnesium + nitric acid ➡ magnesium nitrate + hydrogen
Mg + 2HNO3 ➡ Mg(NO3)2 + H2

Question 2

What is the equation for a reaction between a metal and water?

Answer 2

metal + water ➡ metal hydroxide + hydrogen
eg. sodium + water ➡ sodium hydroxide + hydrogen
2Na + 2H2O ➡ 2NaOH + H2

Question 3

What is a displacement reaction?

Answer 3

a reaction where a more reactive metal takes the place of a less reactive metal on a compound

Question 4

What is the displacement equation of:

1) zinc + lead sulphate
2) copper + silver nitrate

Answer 4

1) zinc + lead sulphate ➡ zinc sulphate + lead
Zn + PbSO4 ➡ ZnSO4 + Pb
2) copper + silver nitrate ➡ copper nitrate + silver
Cu + 2AgNO3 ➡ Cu(NO3)2 + 2Ag

Question 5

What are the principles of metal extraction using the reactivity series?

Answer 5

Potassium, Sodium, Calcium, Magnesium, Aluminium
↪v.reactive, extracted by electrolysis (more reactive than carbon so cannot be displaced by it)
Zinc, Iron, Lead
↪more reactive, extracted by reduction (heating with carbon to remove oxygen)
Copper, Silver, Gold, Platinum
↪unreactive, little/mol extraction needed

Question 6

Describe the extraction process of iron in a blast furnace

Answer 6

▪iron ore, coke and limestone are fed in through the top of the furnace. Hot air us blown in through the bottom. The hot air causes coke to burn
↪ C + O2 ➡ CO2
▪ in the high temperatures, CO2 reacts with coke
↪ CO2 + C ➡ 2CO
▪ the CO then reduces the iron oxide in the iron ore into molten iron
↪3CO + Fe2O3 ➡ 2Fe + 3CO2
▪molten iron flows to the bottom, limestone added removes acidic inpurites. This forms molten slab that floats in molten iron
↪CaCO3 ➡ CaO + CO2
↪CaO + SiO2 ➡ CaSiO3 (slag)

Question 7

Describe the extraction of aluminium by electrolysis

Answer 7

▪remove sand and other impurities
▫ DON’T melt aluminium oxide (has v.high melting point) -> very expensive
▪DO dissolve bauxite into Cryolite
↪aluminium compound with lover melting point
▪electrolyte: solution of aluminium oxide in molten cryolite
▪@cathode: Al3+ + 3e- ➡ Al -> reduced
▪@anode: 2O2- ➡ O2 + 4e- ->oxidized
▪electrodes: carbon