Question #a7e06

1 Answer
Jul 3, 2015

The compound's empirical formula is #C_7H_16#.


Here's how you can determine your compound's empirical formula.

You know that its percent composition is 84% carbon and 16% hydrogen. This means that a 100-g sample of your compound will contain 84 g of carbon and 16 g of hydrogen.

Use carbon and hydrogen's molar masses to determine how many moles of each you'd get in a 100-g sample.

#"For C": (84cancel("g"))/(12.0cancel("g")/"mol") = "7 moles"#

#"For H": (16cancel("g"))/(1.008cancel("g")/"mol") = 15.87 ~= "16 moles"#

The simplest ratio between 7 and 16 is actually #7:16#, which means that the empirical formula looks like this


You get 7 moles of carbon and 16 moles of hydrogen for every 100-g of your compound.