Question

Calculate the percentage by mass of the indicated element in the following compounds.

Carbon in acetylene, C2H2 , a gas used in welding.
Express your answer using three significant figures.

Answer 1

Answer: The mass percent of carbon in acetylene is 92.31 %.

Step-by-step explanation:

In
`C_2H_2`, there are 2 carbon atoms and 2 hydrogen atoms.

To calculate the mass percent of element in a given compound, we use the formula:

`\text{Mass percent of carbon}=\frac{\text{Mass of carbon}}{\text{Molar mass of acetylene}}* 100`

Mass of carbon =
`2* 12g/mol=24g`

Mass of acetylene =
`2* 12g/mol+2* 1g/mol=26g`

Putting values in above equation, we get:-

`\text{Mass percent of carbon}=(24)/(26)* 100=92.31\%`

Hence, the mass percent of carbon in acetylene is 92.31 %.