Combustion analysis of 1.00g of the male sex hormone, testosterone, yields 2.90 g of CO2 and .875 g H2O. What are the mass percents of carbon, hydrogen, and oxygen in testosterone?

How do I solve this?

How many grams of C is in 2.90g of CO2? That is the same mass of C in the 1 gram of testerone.

How many grams of H are in .875 g of water? That is the same mass of H in the 1 gram of testerone.

Now, to figure the O in testostrone, subtract the grams of H and the grams of C from the 1 gram total, the remainder is O.

1 answer

C = 2.90 g/1.00 g = 2.90 g/1.00 g x 100% = 290%

H = .875 g/1.00 g = .875 g/1.00 g x 100% = 87.5%

O = 1.00 g - 2.90 g - .875 g = .225 g/1.00 g x 100% = 22.5%