Question

Acetaminophen is the generic name of the pain reliever in Tylenol and some other headache remedies- The compoundhas the molecular formula C8H9N02. Compute, to four significant figures, the mass percentage of each of the fourelements in acetaminophen.

Answer 1

Answer: The mass percentage of carbon element is 63.57 %, hydrogen element is 5.96 %, nitrogen element is 9.28 % and oxygen element is 21.19 %

Explanation:

We are given:

A chemical compound having chemical formula of $C_8H_9NO_2$. This compound is made by the combination of carbon, hydrogen, nitrogen and oxygen elements.

1 mole of acetaminophen contains 8 moles of carbon atom, 9 moles of hydrogen atom, 1 mole of nitrogen atom and 2 moles of oxygen atom

Mass of carbon element = $(8\times 12)=96g/mol$

Mass of hydrogen element = $(9\times 1)=9g/mol$

Mass of nitrogen element = $(1\times 14)=14g/mol$

Mass of oxygen element = $(2\times 16)=32g/mol$

Mass of the compound = 151 g/mol

To calculate the percentage composition of an element in a compound, we use the equation:

$\%\text{ composition of an element}=\frac{\text{Mass of element}}{\text{Mass of compound}}\times 100$      ........(1)

• For carbon element:

Putting values in equation 1, we get:

$\% \text{ composition of carbon element}=\frac{96}{151}\times 100\\\\\% \text{ composition of carbon element}=63.57\%$

• For hydrogen element:

Putting values in equation 1, we get:

$\% \text{ composition of hydrogen element}=\frac{9}{151}\times 100\\\\\% \text{ composition of hydrogen element}=5.96\%$

• For nitrogen element:

Putting values in equation 1, we get:

$\% \text{ composition of nitrogen element}=\frac{14}{151}\times 100\\\\\% \text{ composition of nitrogen element}=9.28\%$

• For oxygen element:

Putting values in equation 1, we get:

$\% \text{ composition of oxygen element}=\frac{32}{151}\times 100\\\\\% \text{ composition of oxygen element}=21.19\%$

Hence, the mass percentage of carbon element is 63.57 %, hydrogen element is 5.96 %, nitrogen element is 9.28 % and oxygen element is 21.19 %