Percent+Composition

 Percent Composition

Percent compositionis the amount of elements in a compound. This is expressed in mass of each element. Each compositionhas to have a percent value of each of the different elements in the compound.

The percent by mass of an element in a compound as found out by first identifying an element. You look up the atomic mass of the alement and multiply it by however many you have of that element. Add up all the elements together to get the mass of the compound. To get the percent composition of the element you are looking for, put divide that mass of the element over the mass of the entire compound and multiply by 100%.


 * % mass of element = (mass of element/mass of compound) X 100%

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Practice Problem!

A compound is formed when 9.03 g Mg combines completetly with 3.48 g N. What is the percent composition of this compound? media type="file" key="Movie.wmv" When a 14.2-g sample of mercury(II) oxide is decomposed into its elements by heating, 13.2 g Hg is obtained. What is the percent composition of the compound? media type="file" key="Movie_0001.wmv" Calculate the percent composition of ethane (C2H6).

Calculate the percent composition of sodium hydrogen sulfate (NaHSO4).