Question

A graduated cylinder was filled with water to the 25.0 mL mark and weighed. Its mass was 105.5g. An object made of an unknown metal was placed in the cylinder and completely submerged in the water. The water level rose to 30.7 mL. When reweighed, the cylinder, water and metal object had a total mass of 156.0g. Based on these measurement, what is the density of the unknown metal?

Answer 1

The answer is 8.9 g/mL.

The density (D) is equal to mass (m) divided by volume (V): D = m/V

Let's find the mass of the object:
m = 156 g - 105.5 g = 50.5 g

Let's find the volume of the volume:
V = 30.7 mL - 25 mL = 5.7 mL

The density is:
D = m/V = 50.5 g  / 5.7 mL = 8.9 g/mL