A hydrocarbon is burnt completely to give 3.447g of
C
O
2
and 1.647g of
H
2
O
. What is the empirical formula ?

The empirical formula for the given compound is

Explanation:

The chemical equation for the combustion of compound having carbon, hydrogen, iron and oxygen 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 44g of carbon dioxide, 12 g of carbon is contained.

So, in 3.447 g of carbon dioxide, of carbon will be contained.

For calculating the mass of hydrogen:

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

So, in 1.647 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 0.0783 moles.

For Carbon =

For Hydrogen =

The ratio of C : H = 1 : 2

Hence, the empirical formula for the given compound is

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.