Question

Chemical Make up of One of Chloroform

Element	Number of Moles	Mass per Mole (grams)
Carbon	1	12.011
Hydrogen	1	1.008
Chlorine	3	35.453

A chemical solvent is a substance that dissolves another to form a solution. For example, water is solvent for sugar. Unfortunately, many chemical solvents are hazardous to the environment. One eco-friendly chemical solvent is chloroform, also known as trichloromethane ($CH{Cl}_3$). The table above shows the chemical makeup of one mole of chloroform.
Carbon makes up what percent of the mass of one mole chloroform? Round your answer to the nearest whole percent and ignore the percent sign when entering your answer

• A. $15$
• B. $10$
• C. $16$
• D. $18$

Answer 1

The correct option is B $10$

To use the formula, find the part of the mass represented by the carbon; there is $1$ mole of carbon, and it has a mass of $12.011$ grams.

Next, find the whole mass of the mole of chloroform; $1$ mole carbon $\left(12.011g\right)+1$ mole hydrogen$\left(1.008g\right)+3$ moles chlorine $(3\times 35.453=106.359g)=12.011+1.008+106.359=119.378$.

Now use the formula:

Percent $=$ $\frac{part}{whole}\times 100$%

Percent $=$ $\frac{12.011}{119.378}\times 100$%

Percent $=$ $0.10053\times 100$%

$=10.053\%$

Rounding to the nearest whole percent, which is $10$.