Complete combustion of 2.30 g of a hydrocarbon produced 7.39 g of CO2 and 2.52 g of H2O. What is the empirical formula for the hydrocarbon? Insert subscripts as necessary.

C10H17.

Explanation:

To show the proportion of the elements in a compound we make use of empirical formula. In order to calculate the empirical formula we will need atomic mass and the masses of the elements present in the compound. In this question we will make use of mass number of the compounds.

Step one: find the number of moles of the products that is CO2 and H2O.

The number of moles of CO2 = mass / molar mass.

Molar mass of CO2 = 44 g / mol.

number of moles of CO2 = 7.39 / 44.

number of moles of CO2 = 0.168 moles CO2.

===> number of moles of H2O = 2.52 / 18.

= number of moles of H2O = 0.14 moles.

Step two:

Find the moles of the elemental Hydrogen and Carbon in water and Carbondioxide respectively.

For carbon, the number of moles = 0.168 * 1 mole of carbon / 1 mole of CO2. = 0.168 moles carbon.

For Hydrogen, the number of moles = 0.14 * 2 moles of hydrogen (in H2O). = 0.28 moles of Hydrogen.

Step three: divide each elemental moles by the smallest mole that is;

For carbon; 0.168 / 0.168 = 1.

For Hydrogen; 0.28 / 0.168 = 1.67. which is equal to 1.7 Approximately.

Since the subscript 1.7 is not a whole number we will try to multiply it by the smallest possible whole number to get a whole number subscript.

Therefore, the empirical formula = C10H17.

C3H5

Explanation:

Since it's a hydrocarbon, it contains only carbon and hydrogen. We proceed to deduce it's empirical formula as follows:

From the mass of carbon iv oxide produced, we can get the number of moles of carbon produced. We first divide the mass by the molar mass of carbon iv oxide. The molar mass of carbon iv oxide is 44g/mol

The number of moles of carbon iv oxide is 7.39/44 = 0.168

Since there is only one carbon atom in CO2, the number of moles of carbon is same as above

From the mass of water produced, we can obtain the number of moles of hydrogen. The number of moles of water produced is 2.52/18 = 0.14

Since there are two moles of hydrogen in one mole of water, the number of moles of hydrogen is thus 0.14 * 2 = 0.28 moles

We now proceed to get the actual number of atoms of each of the elements. The ratio of C to H is 0.168:0.28

= 0.6:1

Let's multiply through by 5 to get a whole number = 3:5

The empirical formula is thus C3H5