Here we're going to say that mass percent, also known as weight percent, is a percentage of a given element in a compound. Now we're going to say here it deals with the molar mass in grams of the selected element and 1 mole of the compound. So this translates to say that mass percent equals the mass or grams of an element divided by the grams of the compound used, then multiplying that by 100. Using this helps us to determine the percent composition of any particular element within a given compound.
Mass Percent - Online Tutor, Practice Problems & Exam Prep
Mass Percent is the percentage of a particular element within a compound.
Mass Percent
Mass Percent Concept
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Mass Percent Example
Video transcript
Here it says to calculate the mass percent of carbon within sodium carbonate. So sodium carbonate is Na2CO3. We're looking for the mass percent of carbon, so that means we're gonna need the grams of carbon over the grams of the compound itself times 100. Alright. So sodium carbonate has within it 2 sodiums, 1 carbon, and 3 oxygens. We're gonna multiply them each by their atomic masses from the periodic table. So sodium is 22.99 grams, carbon is 12.01 grams and oxygen is 16 grams. So multiplying them out we get 45.98 grams, 12.01 grams, and 48 grams. Add them all together, that comes out to 105.99 grams. Take those numbers. So for carbon, its mass is 12.01, and for the compound itself it's 105.99. So we do:
12.01 105.99 × 100When we do that, we get 11.3% as the mass percent of carbon within sodium carbonate.
Determine the percent composition of nitrogen and oxygen with nitrogen dioxide, NO2.