Question #a7e06

1 Answer
Jul 3, 2015

The compound's empirical formula is C_7H_16C7H16.

Explanation:

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

C_7H_16

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