Answer to Question #281050 in Chemistry for Naz

Question

 A combustion process of a 100 mol of solid mineral with 325 mole of pure oxygen is

producing ferric oxide and sulfur trioxide gases. The solid mineral contains of 82 mole% iron

pyrites (FeS2) and 18 mole% inerts.

a) Write the chemical equation for the combustion process.

b) Calculate;

i.

The limiting reactant.

ii.

The percentage of excess.

iii.

The extent of reaction, ξ if complete reaction occurred

Answer 1

2FeS₂ + 7O₂ = 2FeO + 4SO₃

1) According to the equation, 2 moles of FeS₂ require 7 moles of O₂. Therefore,

82 moles of iron pyrites (FeS₂) require: n (O₂) = 7 x n (FeS₂) / 2 = 287 moles.

According to this, FeS₂ is the limiting reactant, O₂ is in excess.

2) n (O₂)_excess = 325 - 287 = 38 moles

n (O₂)_%excess = 38 / 287 x 100 = 13.2%

3) Extent of reaction is a quantity that measures the extent to which the reaction proceeds.