Question

learning: molecules and compounds calculations
question ⓘ
percent mass composition involves calculating the percentage of mass for each of the individual elements in a given substance.
which element has a percent mass composition of 54.51% in vitamin c, $ce{c_{6}h_{8}o_{6}}$?
answer
○ c
○ h
○ o
○ i dont know yet

Explanation:

Step1: Calculate molar mass of $\text{C}_6\text{H}_8\text{O}_6$

First, use atomic masses: $\text{C}=12.01\ \text{g/mol}$, $\text{H}=1.008\ \text{g/mol}$, $\text{O}=16.00\ \text{g/mol}$

$$\begin{align*} \text{Molar mass} &= (6\times12.01) + (8\times1.008) + (6\times16.00)\\ &=72.06 + 8.064 + 96.00\\ &=176.124\ \text{g/mol} \end{align*}$$

Step2: Calculate % mass of C

Divide total mass of C by molar mass, multiply by 100.

$$ \% \text{C} = \frac{6\times12.01}{176.124} \times 100 = \frac{72.06}{176.124} \times 100 \approx 40.91\% $$

Step3: Calculate % mass of H

Divide total mass of H by molar mass, multiply by 100.

$$ \% \text{H} = \frac{8\times1.008}{176.124} \times 100 = \frac{8.064}{176.124} \times 100 \approx 4.58\% $$

Step4: Calculate % mass of O

Divide total mass of O by molar mass, multiply by 100.

$$ \% \text{O} = \frac{6\times16.00}{176.124} \times 100 = \frac{96.00}{176.124} \times 100 \approx 54.51\% $$

Answer:

O. O