# How can I calculate the mass percent of carbon, nitrogen and oxygen in acetamide, #C_2H_5NO#?

##### 1 Answer

The mass percent of a molecule shows the amount each element contributes to the total molecular mass.

The first step in determining the mass percent of a given molecule is to determine each of the molecule component atoms' atomic mass. Since acetamine is composed of carbon, nitrogen, oxygen and hydrogen, we get

**12.0 g/mol**

**14.0 g/mol**

**16.0 g/mol**

**1.00g/mol**

Each element's mass contribution is determined by multiplying the number of atoms of a certain element with its molar mass

**Carbon** contributes **g/mol**;

**Nitrogen** contributes **g/mol**;

**Oxygen** contributes **g/mol**;

**Hydrogen** contributes **g/mol**

Adding each element's contribution gives us the molecule's total atomic mass

**g/mol**

The final step to determining the molecul's mass percent is to divide each elemnt's contribution by acetamide's molar mass and to multiply the result by 100%

Mass percent of **Carbon** =

Mass percent of **Nitrogen** =

Mass percent of **Oxygen** =

Mass percent of **Hydrogen** =

Always check the validity of the answer by adding up all the percentages

So, acetamide is 40.7% Carbon, 23.7% Nitrogen, 27.1% Oxygen, and 8.5% Hydrogen...