A 2.007 g sample of a hydrocarbon is combusted to give 1.389 g of H 2O and 6.785 g of CO 2. What is the empirical formula of the compound? a. CH2 b. C2Hw c. C3H4 d. CH e. C5H12

The empirical formula for the given compound is CH

Explanation:

The chemical equation for the combustion of hydrocarbon follows:

where, 'x', and 'y' are the subscripts of Carbon and hydrogen respectively.

We are given:

Mass of

Mass of

We know that:

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44 g of carbon dioxide, 12 g of carbon is contained.

So, in 21.33 g of carbon dioxide, of carbon will be contained.

For calculating the mass of hydrogen:

In 18 g of water, 2 g of hydrogen is contained.

So, in 4.366 g of water, of hydrogen will be contained.

To formulate the empirical formula, we need to follow some steps:

Moles of Carbon =

Moles of Hydrogen =

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.154 moles.

For Carbon =

For Hydrogen =

The ratio of C : H = 1 : 1

Hence, the empirical formula for the given compound is CH

the answer would be a