Percent composition -Percentage by mass of a "species" in a chemical formula
Basicly, it's similar as the way we calculate our mark percentage :)Ex. Keith has gotten 18 out of 24 mark in Biology 11, so if he wants to calculate what exactly percentage he gets, he can determine it by this formula: (what you get from an example / what a total number, marks in an example) x 100%
As the formula from below, we can plug in (18/24) x 100% = 75% ：) Done!
Back to the percent composition,
Ex) What percentage composition of H2O?
＊Assume you have one mole
Total molar mass 18g/mol
Molar mass of H2 = 1+1 = 2g/mol
Molar mass of O = 16g /mol
Percent of H2 = (2/18) x 100% = 11.1%
Percent of O = (16/18) x100% = 88.9%
Basicly, it's similar as the way we calculate our mark percentage :)Ex. Keith has gotten 18 out of 24 mark in Biology 11, so if he wants to calculate what exactly percentage he gets, he can determine it by this formula: (what you get from an example / what a total number, marks in an example) x 100%
As the formula from below, we can plug in (18/24) x 100% = 75% ：) Done!
Back to the percent composition,
Ex) What percentage composition of H2O?
＊Assume you have one mole
Total molar mass 18g/mol
Molar mass of H2 = 1+1 = 2g/mol
Molar mass of O = 16g /mol
Percent of H2 = (2/18) x 100% = 11.1%
Percent of O = (16/18) x100% = 88.9%
As the blog video insert function doesn't work :( , Let's go to the link from below and take a look the SHORT VIDEO :)
http://www.youtube.com/watch?v=e11mq1BYlcI
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