(i) Roasting: It is the process of heating sulphide ore in the presence of excess of air to form oxide. 2MS + 3O₂ ⟶ 2MO + 2SO₂↑ Calcination: It is the Process of heating carbonate ore in the presence of limited supply of air to form oxide. MCO₃ ⟶ MO +CO₂↑ (ii) Copper can be refined by electrolytic mRead more
(i) Roasting: It is the process of heating sulphide ore in the presence of excess of air to form oxide.
2MS + 3O₂ ⟶ 2MO + 2SO₂↑
Calcination: It is the Process of heating carbonate ore in the presence of limited supply of air to form oxide.
MCO₃ ⟶ MO +CO₂↑
(ii) Copper can be refined by electrolytic method. The electrolyte is a solution of copper sulphate. Cathode is a strip of pure copper. Anode is impure copper
Metals like copper and silver appear to be dull because of corrosion due to sulphur, carbon dioxide and moisture present in the atmosphere. Brightness of the metals can be restored by rubbing with a cloth moistened with a dilute acid.
Metals like copper and silver appear to be dull because of corrosion due to sulphur, carbon dioxide and moisture present in the atmosphere.
Brightness of the metals can be restored by rubbing with a cloth moistened with a dilute acid.
(i) Differentiate between calcination and roasting. (ii) Suggest a method of refining of copper.
(i) Roasting: It is the process of heating sulphide ore in the presence of excess of air to form oxide. 2MS + 3O₂ ⟶ 2MO + 2SO₂↑ Calcination: It is the Process of heating carbonate ore in the presence of limited supply of air to form oxide. MCO₃ ⟶ MO +CO₂↑ (ii) Copper can be refined by electrolytic mRead more
(i) Roasting: It is the process of heating sulphide ore in the presence of excess of air to form oxide.
See less2MS + 3O₂ ⟶ 2MO + 2SO₂↑
Calcination: It is the Process of heating carbonate ore in the presence of limited supply of air to form oxide.
MCO₃ ⟶ MO +CO₂↑
(ii) Copper can be refined by electrolytic method. The electrolyte is a solution of copper sulphate. Cathode is a strip of pure copper. Anode is impure copper
Zinc oxide reacts with carbon, on heating to form zinc metal and carbon monoxide. Write a balanced chemical equation for this reaction. Name (i) the substance oxidised and (ii) the substance reduced.
ZnO + c ⟶ Zn + CO ZnO is reduced to zinc metal. C is oxidised to CO.
ZnO + c ⟶ Zn + CO
See lessZnO is reduced to zinc metal.
C is oxidised to CO.
Write the chemical name and formula of gypsum. What happens when gypsum is heated at 373 K? Write chemical equation for the reaction.
Chemical name: Calcium sulphate hydrated Formula: CaSO₄.2H₂O On heating gypsum at 373 K, gypsum changes to plaster of Paris. ∆ CaSO₄.2H₂O ⟶ CaSO₄.1/2 H₂O+ 3/2 H₂O 373k
Chemical name: Calcium sulphate hydrated
See lessFormula: CaSO₄.2H₂O
On heating gypsum at 373 K, gypsum changes to plaster of Paris.
∆
CaSO₄.2H₂O ⟶ CaSO₄.1/2 H₂O+ 3/2 H₂O
373k
Metals are said to be shiny. Why do metals generally appear to be dull? How can their brightness be restored?
Metals like copper and silver appear to be dull because of corrosion due to sulphur, carbon dioxide and moisture present in the atmosphere. Brightness of the metals can be restored by rubbing with a cloth moistened with a dilute acid.
Metals like copper and silver appear to be dull because of corrosion due to sulphur, carbon dioxide and moisture present in the atmosphere.
See lessBrightness of the metals can be restored by rubbing with a cloth moistened with a dilute acid.
Name any two conventional sources of energy.
Two conventional sources of energy are fossil fuels like coal, petroleum, etc., and the sun.
Two conventional sources of energy are fossil fuels like coal, petroleum, etc., and the sun.
See less