Question 20

The mass of ethyl alcohol that will exactly fill a 200.0 mL container is 157.8 g.

To find the mass of ethyl alcohol that fills a 200.0 mL container, we can use its density, which is approximately 0.789 g/mL. Multiplying the volume by the density gives us the mass: 200.0 mL × 0.789 g/mL = 157.8 g.

A) 157.8 g

This option is correct as it accurately reflects the calculated mass of ethyl alcohol for the specified volume. The calculation confirms that 200.0 mL of ethyl alcohol, when multiplied by its density of 0.789 g/mL, results in a mass of 157.8 g.

B) 25.49 g

This option is incorrect. It represents a much lower mass than what would be expected for 200.0 mL of ethyl alcohol. The calculation of mass based on the given density clearly shows that this value does not align with the correct computation.

C) 0.39 g

This option is also incorrect. It indicates an exceedingly low mass that is not feasible for the volume of ethyl alcohol in question. The density calculation proves that the mass must be significantly higher than this figure.

D) None of the above

This option is incorrect because option A provides a valid and accurate answer. Since the mass of ethyl alcohol that fills the container is indeed 157.8 g, the assertion that none of the options are correct is false.

Conclusion

The correct answer of 157.8 g is verified through proper calculation using the density of ethyl alcohol. All other options fail to reflect the accurate mass that corresponds to the given volume, making option A the only viable choice. This reinforces the importance of applying density to determine mass in volumetric measurements.