680 ml of linseed oil has a mass of 632 g. what is the density of the linseed oil

To find the density, I always say, "density is a broken heart". The reason is that it's mass over volume. 

Ex: D = m/ v

In your problem, it's:

D = 632g/ 680 mL

To find the density of the Linseed oil, divide the volume by mass.

680mL/ 632g = 1.07

Now that you have your answer, you need to have the correct units. Since you have two different units, you'd use those both. So, your answer will be grams over mL.

The density of the Linseed oil is 1.07g/mL

I hope I helped :)
             

D)can be increased in a closed system