Finding density with g and mL

Question

You add 7.6g of iron to 25.50mL of water and observe that the volume of them together is 26.47mL. Calculate the density of iron. Express your answer in 2 significant figures and appropriate units.

Answer 1

Density = mass / volume = g / mls

We know the grams = 7.6 g

The volume is that volume of water that is displaced by the iron, i.e. 26.46 ml - 25.50 ml = 0.96 mls

(See Archimedes Principle)

Density = 7.6 g / 0.96 mls = 7.9 g / ml