Experiment 10 — Win the Metal from Its Ore

Topic: Chemistry · Class 10 · Metals and non-metals: extraction and the reactivity series

Aim: Choose the correct extraction method for all three metals.

Daily: India’s aluminium smelters are built beside power stations for a reason you are about to discover, and iron has been won from its ore in this country for well over two thousand years.

Na: Sodium is too reactive to be displaced by carbon, so it is obtained by electrolysis of its molten salt . The same is true of potassium, calcium, magnesium and aluminium — which is why aluminium smelters need enormous amounts of electricity.

Fe: Iron sits in the middle of the series: its ore is first roasted or calcined to the oxide, then reduced with carbon (coke) in a blast furnace.

Hg: Mercury is very low in the series, so its sulphide ore needs only to be heated in air ; the oxide formed decomposes to the metal on further heating.

Question: Why is aluminium not extracted by reduction with carbon?

Exp: Highly reactive metals need electrolysis of the molten compound.

Question: Roasting is the heating of a … ore in air.

Exp: Calcination is for carbonate ores in limited air.

Question: Metals low in the reactivity series are extracted by…

Exp: Mercury and copper are examples.

Question: Ionic compounds conduct electricity when…

Exp: The ions must be free to move.

Question: Galvanising protects iron by coating it with…

Exp: Zinc corrodes in preference to the iron.