Question

A compound that contains only carbon, hydrogen, and oxygen is 48.64% C and 8.16% H by mass. What is the empirical formula of this substance? 84. The most common form

Answer 1

The empirical formula of this substance is:

`C_3H_6O_2`

Step-by-step explanation:

To find the empirical formula of this substance we need the molecular weight of the elements Carbon, Hydrogen and Oxygen, we can find this information in the periodic table:

- C: 12.01 g/mol

- H: 1.00 g/mol

- O: 15.99 g/mol

With the information in this exercise we can suppose in 100 g of the substance we have:

C: 48.64 g

H: 8.16 g

O: 43.2 g (100 g - 48.64g - 8.16g= 43.2 g)

Now, we need to divide these grams by the molecular weight:

`C=(48.64g)/(12.01 g/mol) =4.05 mol\\H=(8.16g)/(1.00g/mol)= 8.16 mol\\O=(43.2g)/(15.99 g/mol) = 2.70 mol`

We need to divide these results by the minor result, in this case O=2.70 mol

`C=(4.05mol)/(2.70mol)= 1.5\\H= (8.16mol)/(2.70 mol) = 3.02 \\O=(2.70mol)/(2.70mol) = 1`

We need to find integer numbers to find the empirical formula, for this reason we multiply by 2:

`C= 1.5*2=3\\H= 3.02*2= 6.04 \\O= 1*2=2`

This numbers are very close to integer numbers, so we can find the empirical formula as subscripts in the chemical formula:

`C_3H_6O_2`