Question

You had been given a new penny to test if it is made up of pure copper or not. You measured the mass of the penny which was 2.49 g. You then find that the penny displaces 0.349 cm3 of water. Is the penny made of pure copper? (Density of pure copper = 8.96 g/cm3)

Answer 1

In this question we are given the mass and the volume of water displaced by the penny, and we are also given the density, so if the calculated density is different from the previously tested density, therefore the penny is not made of pure copper. Even though cm3 is equal to mL, the answer might still be in cm3, but it is important to know

1 cm3 = 1 mL

Now the formula for density is:

ρ = m/v

where:

m = mass in grams

v = volume in cm3

ρ = 2.49/0.349

ρ = 7.13 g/cm3, since the density is a little lower than the density of pure copper, we don't have a pure copper penny in this case