7) Find the mass of 250.0 mL of benzene. The density of benzene is 0.8765 g/mL.

250 mL x (0.8765 g/mL) = 219.125 g (219.1 g if you're using sigfigs)

219.125 kg.

Explanation:

Density: This can be defined as the ratio of mass of a body to the nolume of the body.

The Formula of density is given as,

D = m/v ... Equation 1

Where D = Density of benzene, m = mass of benzene, v = volume of benzene.

Make m the subject of the equation

m = Dv ... Equation 2

Given: D = 0.8765 g/mL, v = 250 mL.

Substitute into equation 2

m = 0.8765*250

m = 219.125 kg.

Hence the mass of benzene = 219.125 kg.