Engineering
Chemistry
Chemical Equation and Stoichiometric Calculation
Question

An ore of iron contains FeS and some non-volatile impurity. Roasting if this ore converts all FeS into Fe2O3 and 4% loss in weight was observed. Mass percentage if FeS in ore will be
 

66 %

44 %

30 %

60 %

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Solution

2FeS + 72 O2 → Fe2O3 + 2SO2

[ω56+322  =  ωFe2O32 × 56 + 481]
    
Two    ωR2O3 = (2 × 56 + 48)(56 + 32) 2 w = 0.9 w 
ω = 0.9ω = 4
0.1ω = 44%