The flow chart below outlines some of the process involved in extraction of copper from pyrites. Study it and answer the questions that follows.

1. The flow chart below outlines some of the process involved in extraction of copper from pyrites. Study it and answer the questions that follows.

a)

i) Name gas "X"
Gas X ni sulfur dioxide ($\text{SO}_2$).

ii) Write an equation for the reaction that takes place in the 1st roasting furnace.

$$2\text{CuFeS}_2(s) + 4\text{O}_2(g) \to \text{Cu}_2\text{S}(s) + 2\text{FeO}(s) + 3\text{SO}_2(g)$$

iii) Write the formula of the cations present in the slag "M"
Cation iliyopo kwenye slag M ni $\boxed{\text{Fe}^{2+}}$.

iv) Identify gas "P"
Gas P ni sulfur dioxide ($\text{SO}_2$).

v) What name is given to the reaction that takes place in chamber N? Give a reason for your answer.
Jina la mmenyuko unaofanyika katika chumba N ni bessemerisation au auto-reduction (kujipunguza).
Sababu: Copper(I) sulfide ($\text{Cu}_2\text{S}$) humenyuka na copper(I) oxide ($\text{Cu}_2\text{O}$) iliyoundwa kutokana na oxidation ya sehemu ya $\text{Cu}_2\text{S}$ ili kutoa shaba safi na sulfur dioxide bila kuhitaji wakala wa kupunguza kutoka nje.

b) The copper obtained "N" is not pure. Draw a labeled diagram to show the set up you would use to refine the copper by electrolysis.
(Diagram haiwezi kuchorwa hapa, lakini maelezo ya mpangilio ni kama ifuatavyo):

• Anode: Shaba chafu (impure copper)
• Cathode: Shaba safi (pure copper)
• Electrolyte: Larutan ya copper(II) sulfate ($\text{CuSO}_4$) iliyotiwa asidi (acidified)
• Power supply: Chanzo cha umeme wa moja kwa moja (DC power supply) Katika mpangilio huu, anode ya shaba chafu hupungua, ikitoa ioni za $\text{Cu}^{2+}$ kwenye electrolyte, huku uchafu mwingine ukianguka chini kama tope la anode. Kwenye cathode, ioni za $\text{Cu}^{2+}$ kutoka kwenye electrolyte hupunguzwa na kuweka shaba safi.

c) Given that the mass of copper obtained from the above extraction was 210 kg. Determine percentage purity of the ore (Copper pyrites) if 810 kg of it was fed to the 1st roasting furnace.
Molar mass ya $\text{CuFeS}_2 = 63.5 (\text{Cu}) + 56 (\text{Fe}) + 2 \times 32 (\text{S}) = 63.5 + 56 + 64 = 183.5 \text{ g/mol}$
Molar mass ya $\text{Cu} = 63.5 \text{ g/mol}$

Kutoka fomula ya $\text{CuFeS}_2$, mole 1 ya $\text{CuFeS}_2$ hutoa mole 1 ya $\text{Cu