What volume of water has the same mass as 9.0m3 of ethyl alcohol?

This question requires the knowledge of density.

The density of ethyl alcohol = 789 kg m⁻³

The density of water = 1000 kg m⁻³

Density = Mass / Volume

By applying ethyl alcohol,

789 kg m⁻³ = Mass / 0.9 m³

Mass = 710.1 kg

hence the mass of 0.9 m³ ethyl alcohol is 710.1 kg.

Then by applying water,

1000 kg m⁻³ = 710.1 kg / Volume

Volume = 0.7101 m³

= 0.7 m³

hence the equal water volume is 0.7 m³