A 14.60g sample of an unknown compound, composed only of carbon, hydrogen, and oxygen, produced 28.6g of CO2 and 14.6g of H2O in a combustion analysis. What is the mass percent composition of oxygen of the unknown compound?

Explanation:

Let's call the unknown compound X.

1. Calculate the mass of oxygen in 14.60 g of X.

(a) Mass of C

(b) Mass of H

(c) Mass of O

Mass of O = 14.60 - 7.805 - 1.633 = 5.162 g

2. Calculate the mass percent of oxygen

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

a:

by the combination of an unlimited number of elements