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Homework Help: Not understanding how to determine Stoichiometric air to fuel ratio

  1. Jul 5, 2010 #1
    [STRIKE][/STRIKE]1. The problem statement, all variables and given/known data
    Hey, just doing a few problems and i have found i have no understanding of how to solve these types of question, if anyone can help or provide info it would be great thanks...

    Q " The fuel oil supplied to a boiler contains 86% carbon and 14% hydrogen by mass. Determine the stoichiometric air to fuel ratio for complete combustion of the fuel."

    2. Relevant equations

    Composition of air by mass : Oxygen 23% Nitrogen 77%

    Relative Atomic Mass Oxygen (O) 16 , Carbon (C) 12 Hydrogen (H) 1

    3. The attempt at a solution
  2. jcsd
  3. Jul 5, 2010 #2


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    Gold Member

    Consider a basis of 100g of the fuel. Based on the mass percentage composition of the fuel, you should be able to work out how many moles of carbon and hydrogen in this 100g basis.

    You should be able to assume that all of the carbon becomes carbon dioxide and all of the hydrogen becomes water. Based on the molar amounts of carbon and hydrogen, you can work out how much water and carbon dioxide will form and thus the amount of oxygen consumed.

    Can you work from there?
  4. Jul 5, 2010 #3
    So basically create an equation and then sub in the molar amounts??
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