Question

CH 2) A geologist brought in a sample of ore containing Fe(HCO) and some other, unreactive material. If the sample weighed 1.394 8. and after decomposition weighed 0.97%. What is the % FeHCO), of the sample? dan - 3) If 2.112 g of FeO, reacts with 0.687 g of Al, how much pure Fe will be produced? Fe,0,() + 2 Al(s) - A1,0, (s) + 2 Fe (8)

Answer 1

2Fe(HCO3)3(s) ----------------> Fe2(CO3)3 + 3H2CO3

The mass of H2CO3    = 1.394-0.978   = 0.416g

3 moles of H2CO3 produced from 2 moles of Fe(HCO3)3

3*62g of H2CO3 produced from 2*239g of Fe(HCO3)3

0.416g of H2CO3 produced from = 2*239*0.416/(3*62)   = 1.07g of Fe(HCO3)3

%Fe(HCO3)3   = 1.07*100/1.394   = 76.76%

part-B

no of moles of Fe2O3 = W/G.A.Wt

   = 2.112/159.69    = 0.0132 moles

no of moles of Al = W/G.A.Wt

                             = 0.687/27 = 0.0254moles              

Fe2O3(s) + 2Al(s) ---------------> Al2O3(s) + 2Fe(s)

1 mole of Fe2O3 react with 2 moles of Al

0.0132 moles of Fe2O3 react with = 2*0.0132/1   = 0.0264 moles of Al is required

Al is limiting reactant

2 moles of Al react with excess of Fe2O3 to gives 2 mole of Fe

0.0254 moles of Al react with excess of Fe2O3 to gives = 2*0.0254/2   = 0.0254 moles of Fe

mass of Fe = no of moles * gram atomic mass

                   = 0.0254*55.845

                    = 1.42g of Fe >>>.answer