Here's how to do it:
-- Make a vertical column (Column 1) and list your various gas components (as C4H10, C3H8, C2H6, etc.) from top to bottom of list.
-- Make Column 2 (just to the right of Column 1) and using your weight percentages, list the mass of each component (as 1.75 for butane, 95.00 for propane, 1.20 for ethane, etc.). This column must add up to 100.00 when done.
-- Make Column 3 (just to the right of Column 2) and divide the mass of each component by the molecular weight of that component (1.75 divided by 58 for butane, 95.00 divided by 44 for propane, etc.) which gives you the mols of each component and list those moles from top to bottom of that column. Add up that column and enter the total at the bottom.
-- For a gas, mole percent is equal to volume percent. So now, make Column 4 (just to the right of Column 3) and calculate the mole percent of each component. Column 4 must add up to 100.00. If not, you made an arithmetic error somewhere.
You can set it up on a spreadsheet ... but that will take you longer to do, than just going ahead with paper and pencil and working it out. It's very simple!Keep in mind, mole percent = volume percent only for gases. Don't try the above method with liquids.
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