A chemist mixes 53.8 g of carbon tetrachloride with 50.0 g of 2-ethyltoluene and 72.8 g of isopropenylbenzene.

Calculate the percent by mass of each component of this solution.
Round each of your answers to 3 significant digits.
Carbon tetrachloride?
2-ethyltoluene?
Isopropenylbenzene?

1 answer

To calculate the percent by mass of each component in the solution, we'll first find the total mass of the mixture and then determine the mass percent of each component.

  1. Calculate the total mass of the mixture: \[ \text{Total mass} = \text{mass of carbon tetrachloride} + \text{mass of 2-ethyltoluene} + \text{mass of isopropenylbenzene} \] \[ \text{Total mass} = 53.8 , \text{g} + 50.0 , \text{g} + 72.8 , \text{g} = 176.6 , \text{g} \]

  2. Calculate percent by mass for each component:

    • Carbon tetrachloride: \[ \text{Percent by mass} = \left( \frac{\text{mass of carbon tetrachloride}}{\text{total mass}} \right) \times 100 \] \[ \text{Percent by mass (CCl}_4\text{)} = \left( \frac{53.8 , \text{g}}{176.6 , \text{g}} \right) \times 100 \approx 30.5% \]

    • 2-Ethyltoluene: \[ \text{Percent by mass} = \left( \frac{\text{mass of 2-ethyltoluene}}{\text{total mass}} \right) \times 100 \] \[ \text{Percent by mass (C}9\text{H}{12}\text{)} = \left( \frac{50.0 , \text{g}}{176.6 , \text{g}} \right) \times 100 \approx 28.3% \]

    • Isopropenylbenzene: \[ \text{Percent by mass} = \left( \frac{\text{mass of isopropenylbenzene}}{\text{total mass}} \right) \times 100 \] \[ \text{Percent by mass (C}9\text{H}{10}\text{)} = \left( \frac{72.8 , \text{g}}{176.6 , \text{g}} \right) \times 100 \approx 41.2% \]

  3. Summary of Percent by Mass:

    • Carbon tetrachloride: 30.5%
    • 2-Ethyltoluene: 28.3%
    • Isopropenylbenzene: 41.2%

All values are rounded to three significant digits as requested.