Physics: What is the density of the unknown liquid?

Question

A 85.0 g bottle is filled half full with 1.00 L of water. It is filled the rest of the way will an unknown liquid. The total mass of this full bottle is 1.75 kg, what is the density of the unknown liquid?

Answer 1

Hello Homework (what an interesting name!),

The total mass is 1.75kg or 1750g.

Subtracting the masses of the bottle (85.0g) and the 1L of water (1000.g) will find the mass of the unknown liquid.

1750g - 85.0g - 1000.g = 665g of unknown liquid.

Since 1L of water half filled the bottle, the unknown liquid will also be 1L to fill the other half of the bottle.

So the density  of the unknown liquid is 665g/L.