What are the equitations for Mass and Volume?

Question

Chem homework =]

When I looked them up, it said that Density = Mass / Volume, but then it said that Mass = Density X Volume. How do I find one without the other?!?!

Answer 1

With Algebra:

Density = D

Volume = V

Mass = M

D = M/V  

Multiply the both sides by V to get rid of the V in the denominator on the right hand side as shown below:

V * D = M/V * V = M  --> Now we have M = V * D as stated!

We could rearrange to solve for volume as well as shown below:

D = M/V

D * V = M/V * V = M

(D * V)/D = M/D = V --> Now we have V = M/D

Work on the algebra skillz and you will be in the clear!!!  

Enjoy!!

Answer 2

You have to know atleast 2 of the values to calculate the other one.

Density = Mass / Volume

Mass = Density X Volume

Volume = Density X Mass

You have to wiegh the mass, measure the volume, calculate or use a given density of a substance.