Question

What is the mass percentage of carbon in $\mathrm{CO}$? What is the mass of carbon in $4.9\text{g}$ of $\mathrm{CO}$?

Answer 1

Step 1: Given information

The given compound is $\mathrm{CO}$ (Carbon monoxide).

Mass of $\mathrm{CO}=4.9\mathrm{g}$.

Step 2: Calculation of gram molecular mass of $\mathrm{CO}$

The gram molecular mass of $\mathrm{CO}$=$\left(12+16\right)\text{g=28 g}$

Step 3: Formula used to determine the mass percentage of an element
$\text{Percentage composition by mass}=\frac{\text{Mass of the element in 1 molecule of a compound}}{\text{Gram molecular mass of the compound}}\times 100$

Step 4: Calculation of mass percentage of carbon in $\mathrm{CO}$
$$\begin{gathered} \text{Mass percentage of carbon}=\frac{12\text{g}}{28\text{g}}\times 100 \\ =42.9\% \end{gathered}$$

Step 5: Calculation of mass of carbon in $4.9\text{g}$ of $\mathrm{CO}$.

Since, $28\text{g}$ of $\mathrm{CO}$ contains $12\text{g}$ of carbon.

Therefore, $4.9\text{g}$ of $\mathrm{CO}$ contains $\frac{12\text{g}}{28\text{g}}\times 4.9\text{g=2.1 g}$ of carbon.

Hence, the mass percentage of carbon in $\mathrm{CO}$ is $42.9\%$, and the mass of carbon in $4.9\text{g}$ of $\mathrm{CO}$ is $2.1\text{g}$.