An unknown clear liquid solvent is tested for identification in the lab using
solubility tests. The unknown solvent is either methanol (CH3OH), methane
(CH4), or pentane (C5H12). The unknown liquid is mixed with the following
solutes, NaCl, H20 and C2H6. The solutes that are soluble in the unknown
solvent are NaCl and H20. What is the identification of the solvent?
Methane
Pentane
None are possible
Methanol

6g/mL

Explanation:

Given parameters;

Mass of the unknown substance  = 18g

Volume of water before the mass is introduced  = 5mL

Volume of water after the mass is introduced  = 8mL

Unknown:

Density of the mass = ?

Solution:

Density is the mass per unit volume of a substance.

             Density  =

Mass is the amount of matter in a substance

Volume is the space occupied by a body

Volume of the body  = 8mL - 5mL = 3mL

Insert the parameters and solve;

             Density  =   = 6g/mL