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

2Al2O3 + 3C →   Al+3CO2Gram  equivalent  of Al2O3  =Gram  equivalent  of  C.Now  equivalent  weight  of Al=273=9Equivalent  weight of  C=124=3C0→ C+4O2No.  of  gram  equivalent  of Al=wt.E=270 × 1039=30 × 103Hence,No.  of  gram  equivalent  of C=30 × 103Again,No.  of  gram  equivalent  of C=mass  in  gramgram  equivalent  weight⇒   30  ×  103 = mass3⇒ mass  =  90 ×  103 g=90 kg