Peroxyacylnitrate (PAN) is one of the components of smog. It is a compound of C, H, N, and O.
Determine the percent composition of oxygen and
the empirical formula from the following percent
composition by mass: 19.8 percent C,
2.50 percent
H, 11.6 percent N. What is its molecular formula
given that its molar mass is about 120 g?

C – 19,9%, H – 2,2%, N – 11,6%, O – x%

1 percentage

The entire molecule is 100% and all the components of the compound add up to 100%.

100% - 19,9% - 2,5% - 11,6% = 66,1%

The compound contains 66,1% oxygen.

2 molar masses

3 masses

The compound has a molar mass of 120g/mol. So one molecule weighs 120 g. To find out how much the percentage of a component weighs, you have to calculate it using the molar mass.

carbon

19,8% of 120g

One molecule contains 23,76g of carbon.

hydrogen

2,5% of 120g

One molecule contains 3g of hydrogen.

oxygen

66,1% of 120g

One molecule contains 79,32g of oxygen.

nitrogen

11,6% of 120g

One molecule contains 13,92g of nitrogen.

4 amount of substance

carbon

The compound contains about 2 moles of carbon.

hydrogen

The compound contains about 3 moles of hydrogen.

oxygen

The compound contains about 5 moles of oxygen.

nitrogen

The compound contains about 1 moles of nitrogen.

5. molecular formula

The formula results from the ratio of the amounts of substance.

a small container that holds a source of energy a solar cell that captures light energy and converts it into electricity a voltaic cell that uses the oxidation of a fuel to produce electricity

explanation:

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.