Question

A 230 g sample of a compound contains 136.6 g of carbon, 26.4 g of hydrogen, and 31.8 g of nitrogen. The rest is oxygen. What is the mass percent of oxygen in the compound? 11.48%

Answer 1

If the total amount of the sample is 230g and they give each component of the sample, we add the given amount of grams of each element and subtract the given from 230g.

$136.6+26.4+31.8 = 194.8$
$230-194.8=35.2$

That means the rest of oxygen is 35.2g

This is Percent Composition.

The formula to find the percent composition of an element inside a compound is $\frac {MolarMass Of Element}{MolarMass Of Compound}*100$

Now we implement the variables into the formula to find the percent composition oxygen.

$\frac {35.2}{230} *100 =15.30$

The answer is 15.30% = O