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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: walkerke on February 08, 2005, 07:13:39 PM

Title: combustion with percent yeild?
Post by: walkerke on February 08, 2005, 07:13:39 PM

So Here is the problem:
Limestone(CaCO3) is used to remove acidic pollutants from smokestack flue gases in a sequence of decomposition-combination reactions. The limestone is heated to form lime (CaO), which reacts with sulfur dioxide to form calcium sulfite. Assuming a 61.9% yield in the overall reaction, what mass of limestone is required to remove all the sulfur dioxide formed by the combustion of 66000 kg coal that is 0.36 mass % sulfur

I have written the equation and know how to do percent yeild equations but I am so lost when it comes to teh sulfur dioxide part. I don't understand how it all comes together and how I am supposed to figure it out from coal. If you have any suggestions, that would be wonderful. Thank you!

Title: Re:combustion with percent yeild?
Post by: Donaldson Tan on February 09, 2005, 07:00:56 PM

CaCO3 + S + O2 -> CaSO4 + CO2

The yield tells you that CaCO3 is 61.9% effective in removing sulphur, because only 61.9% of the CaCO3 present is used up in removing sulphur. Hence, you must supply more CaCO3 than the stoichiometric ratio suggest.