Question

The percentage of carbon in${\mathrm{CO}}_2$ is:

• A. $0.034\%$
• B. $27.27\%$
• C. $3.4\%$
• D. $28.7\%$

Answer 1

The correct option is B

$27.27\%$

The explanation for the correct option

(B)$27.27\%$

Step1. The formula for mass percentage

$\text{Mass \% of an element =}\frac{\text{mass of that element in the compound ×100}}{\text{molar mass of the compound}}$

Step 2. Calculation of percentage of carbon in${\mathrm{CO}}_2$

• The molar mass of ${\mathrm{CO}}_2$=$\left(12+2\times 16\right)\text{g=44 g}$
• $$\begin{gathered} \text{Mass \% of an element =}\frac{12}{44}\text{×100} \\ =27.27\% \end{gathered}$$
• So, the mass percentage of carbon in${\mathrm{CO}}_2$ is $27.27\%$.

The explanation for incorrect options

The mass percentage of carbon in${\mathrm{CO}}_2$ is $27.27\%$. Hence, options (A), (C), and (D) are incorrect.

Hence, option (B) is correct. The mass percentage of carbon in${\mathrm{CO}}_2$ is $27.27\%$.