Question

The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270kg of aluminum metal from bauxite by the Hall process is: (Atomic mass Al = 27)

• A. 180 kg
• B. 120 kg
• C. 360 kg
• D. 90 kg

Answer 1

The Correct Option is D

The balanced chemical equation for the production of aluminum from bauxite is:
2Al₂O₃ + 3C → 4Al + 3CO₂

The molar mass of aluminum (Al) is 27 g/mol.

270 kg of aluminum metal to be produced, which is equivalent to 270,000 grams.

Moles of Al = Mass of Al / Molar Mass of Al
Moles of Al = 270,000 g / 27 g/mol
Moles of Al = 10,000 moles

From the balanced equation, we can see that 3 moles of carbon (C) are required to produce 4 moles of aluminum (Al). Therefore, the mole ratio of C to Al is 3:4.

Now, calculating the moles of carbon required to produce 10,000 moles of aluminum:

Moles of C = (10,000 moles of Al) × (3 moles of C / 4 moles of Al)
Moles of C = 7,500 moles

Now, we need to find the mass of carbon (C) consumed:

Mass of C = Moles of C × Molar Mass of C
Mass of C = 7,500 moles × (12 g/mol)
Mass of C = 90,000 g

So, the mass of the carbon anode consumed in the production of 270 kg of aluminum metal from bauxite by the Hall process is 90,000 grams or 90 kg.

Therefore, the correct option is (D):  90 kg