Question

An organic compound which is commonly found in fragrances and flavors was determined to contain Carbon, Hydrogen, and Oxygen. It contains 64.00% of Carbon and 4.03% of Hydrogen by mass. Determine the empirical formula?

Answer 1

`\begin{gathered} \text{The empirical formula is} \\ C_{3\text{ }}H_2O \end{gathered}`

Explanation:

From the question provided, you were told the organic compound contains Carbon, Hydrogen, and Oxygen

Given information

% by composition of carbon = 64.00%

% by composition of hydrogen = 4.03%

Recall that, the organic compound contains carbon, hydrogen, and oxygen, but you were not given the % by the composition of oxygen.

Note that, the % composition of constituents in a compound is 100%. The next thing is to find the % by the composition of oxygen.

Let the % by the composition of oxygen be x

% by composition of carbon + % by composition of hydrogen + % by composition of oxygen = 100%

64.00% + 4.03% + x% = 100%

68.03% + x% = 100%

Isolate x% by subtracting 68.03% from both sides

68.03% + x% - 68.03% = 100% - 68.03%

x% = 31.97%

x = 31.97%

Therefore, % by composition of oxygen in the organic compound = 31.97%

The next thing is to find the empirical formula

Note that, the molar mass of carbon, oxygen, and hydrogen is given in the periodic table

• Molar mass of carbon = ,12 g/mol

,

• Molar mass of oxygen = ,16g/mol

,

• Molar mass of hydrogen = ,1 g/mol

The next thing is to approximate the mole ratio of each element

Carbon = 3

Hydrogen = 2

Oxygen = 1

Therefore, the empirical formula is given below

`C_3H_2O`