Question

What volume of ethanol (D = 0.789 g/mL) will have the same mass as 56.85 mL of aluminum (D = 2.70 g/mL)?

Answer 1

The equation for density is d = m/V
so
1) from the volume and density of Al calculate the mass of Al
2) this is also the mass ethanol so now from the mass and density of ethanol calculate the volume
(56.85 mL) x (2.70 g/mL) / (0.789 g/mL) = 194.5 mL