An empty beaker and watch glass has a mass of 120.15g. Exactly 25.00 mL of an unknown liquid was added to this beaker and the mass was found. The mass of the beaker, liquid, and cover was 145.50g. What is the density of the liquid?

1.014g/mL

Explanation:

Given parameters:

Mass of beaker and watch glass  = 120.15g

Volume of unknown liquid  = 25mL

Mass of beaker + liquid + cover = 145.50g

Unknown:

Density of the liquid  = ?

Solution:

Density is the mass per unit volume of a substance.

It is mathematically expressed as:

 Density  =  

  Mass of liquid  = Mass of beaker + liquid + cover  - Mass of beaker and watch glass

 Mass of liquid  = 145.50g  - 120.15g  = 25.35g

So;

 Density  =    = 1.014g/mL

since electrons are negative the answer is neagtaive