1)Name the ore of lead and give their formula
2)Why is PbS ground into fine powder before extraction
3)Write the equation when PbS is burnt in oxygen
4)Name the gas produced in the process
5)Name three raw materials used in this process
6)Write an equation to show how coke reduce PbS
7)Why is iron added into the furnace
8)Show using an equation how calcium silicate is formed from calcium oxide
9)Name two compounds that form the slug
10)Explain how ways by which pure lead can be obtained by;i)Use of oxygen
ii)Use of electrolysis
11)Name the electrode material when electrolysis method is used
1) The ore of lead is Galena, with the chemical formula PbS.
2) PbS is ground into a fine powder before extraction to increase the surface area, allowing for better contact with the extracting agent.
3) The equation when PbS is burnt in oxygen is:
PbS + 3O2 -> PbSO4
4) The gas produced in the process is sulfur dioxide (SO2).
5) The three raw materials used in this process are PbS (Galena), oxygen, and a carbon source (such as coke).
6) Equation showing how coke reduces PbS:
PbS + 2C -> Pb + 2CO
7) Iron is added into the furnace to act as a flux, helping to remove impurities from the lead.
8) Equation showing how calcium silicate is formed from calcium oxide:
CaO + SiO2 -> CaSiO3
9) Two compounds that form the slag are calcium silicate (CaSiO3) and lead oxide (PbO).
10) Ways to obtain pure lead:
i) Use of oxygen: Lead can be obtained by heating lead oxide (PbO) in the presence of excess oxygen to produce pure lead metal and oxygen gas.
ii) Use of electrolysis: In this method, lead can be obtained by electrolyzing a solution of lead(II) nitrate (Pb(NO3)2) to deposit pure lead metal at the cathode.
11) The electrode material when electrolysis method is used is usually graphite.