Final answer:
To calculate the mass of benzene, multiply the volume (250 mL) by the density (0.8786 g/mL) to obtain a mass of 219.65 g, which is option a).
Step-by-step explanation:
To find the mass of benzene, you need to multiply its volume by its density. Given the density of benzene as 0.8786 g/mL, the mass of 250 mL of benzene is calculated as follows:
Mass = Volume × Density
Mass = 250 mL × 0.8786 g/mL
Mass = 219.65 g
Therefore, the correct answer is option a) 219.65 g.