Extraction of Metals

Question 1

ZINC SULFIDE

Answer 1

zinc sulfide + oxygen –> zinc oxide + sulfur dioxide 2ZnS + 3O₂ –> 2ZnO + 2SO₂

Question 2

What are the problems and benefits associated with SO₂?

Answer 2

Problems - acid rain

Benefits - can be converted into H₂SO₄ which is high in demand

Question 3

Reduction of Iron(III) Oxide

Answer 3

2Fe₂O₃₍_s) + 3C_(s) –> 4Fe_(l) + 3CO_2(g)

Fe₂O_3(s) + 3CO_(g) –> 2Fe_(l) + 3CO_2(g)

Question 4

Reduction of Manganese(IV) Oxide

Answer 4

MnO_2(s) + C_(s) –> Mn_(l)​ + CO_2(g)

MnO_2(s) + 2CO_(g) –> Mn_(l) + 2CO_2(g)

Question 5

Reduction of Copper Carbonate (direct method)

Answer 5

2CuCO₃₍_s) + C_(s) –> 2Cu_(l) + 3CO_2(g)

Question 6

Reduction of Copper Carbonate (indirect)

Answer 6

CuCO₃₍_s) –> CuO_(s) + CO_2(g)

2CuO_(s) + C_(s) –> 2Cu_(l) + CO_2(g)

Question 7

Extracting Tungsten

Answer 7

CAN’T USE CARBON - MAKES A BRITTLE CARBIDE. WO₃₍_s) + 3H_2(g) –> W_(s) + 3H₂O_(g)

Question 8

What are the hazards involved with using H₂ to extract metals?

Answer 8

Highly explosive when mixed with air

Question 9

Explain why and how Aluminium is extracted.

Answer 9

Too reactive to undergo reduction by carbon. Extracted via electrolysis. Bauxite (Al₂O₃) has impurities removed then dissolved in Na₃AlF₆. This lowers melting point (to reduce operating costs). At cathode: Al³⁺ + 3e⁻ –> Al At anode: 2O²⁻ –> O₂ + 4e⁻ Anode has to be replaced frequently as carbon reacts with oxygen produced.

Question 10

Extracting Titanium.

Answer 10

CAN’T USE CARBON - BRITTLE CARBIDE FORMED Batch process.

Step 1: TiO₂₍_s) + 2Cl_2(g) + 2C_(s) –> TiCl_4(g) + 2CO_(g)

Step 2: TiCl₄ + 4Na_(l) –> Ti_(s) + 4NaCl_(l)

Magneisum can be used instead of sodium.