Question

6. An experiment is carried out to try to distinguish between cylinders of copper, stainless steel and brass on the basis of densities. The densities are 8.93 g/cm for copper, 7.75 g/cmº for stainless steel and 8.40 g/cm for brass. The mass of a metal cylinder is measured to be 42.00 g (4 sig figs), and its volume is measured to be 5 cm (1 sig fig). Why is it not valid to identify the cylinder as being made of brass?

Answer 1

Given

mass of metal cylinder = 42g

volume of the metal cylinder = 5cm³

Density of copper = 8.93 g/cm³

Density of stainless steel = 7.75 g/cm³

Density of brass = 8.40 g/cm³

Density of cylinder = mass/volume

=42.00/5   = 8.4 g/cm³

so the cylinder is made up of brass.