Question

A new penny has a mass of 2.49 g and a volume of 0.349cm3. The density of copper is 8.94 g/mLA)Is the penny made of pure copper?B)The densities of four metals are given below. Based on the density of the penny, which, if any, other metal might be mixed with the copper?gold: 19.3 g/cm3mercury: 13.5 g/cm3lead: 11.3 g/cm3zinc: 7.14 g/cm3

Answer 1

Answer:

Zinc metal might be mixed with the copper.

Explanation:

Density is defined as mass of the substance present in the unit volume of the substance.

$Mass=\frac{Mass}{Volume}$

Density of pure copper = d = 8.94 g/mL = $8.94 g/cm^3$

$1 mL = 1 cm^3$

Mass of the copper penny = M = 2.49 g

Volume of the copper penny = V = $0.349 cm^3$

Density of the copper penny = d

$d=\frac{M}{V}=\frac{2.49 g}{0.349 cm^3}=7.135 g/cm^3$

Density of pure copper > Density of zinc > Density of penny

$8.94 g/cm^3>7.14 g/cm^3>7.135 g/cm^3$

The metal mixed with copper is zinc to make a penny . This is so because all the other metal given have higher value of density which will increase the density of the copper penny if they were present.

But here the density of the copper penny is smaller than density of pure copper which means that less denser metal than copper is also added in the penny.