A cube of gold [tex]\((\text{Au})\)[/tex] has a side length of 1.55 cm. If the sample is found to have a mass of 71.9 g, find the density of [tex]\(\text{Au}\)[/tex].



Answer :

To determine the density of a gold cube given its side length and mass, follow these steps:

1. Calculate the Volume of the Cube:

The volume [tex]\( V \)[/tex] of a cube can be found using the formula for the volume of a cube:
[tex]\[ V = \text{side length}^3 \][/tex]

Given the side length of the cube is 1.55 cm, we can substitute this value into the formula:
[tex]\[ V = 1.55^3 \, \text{cm}^3 \][/tex]

Performing this calculation, we obtain:
[tex]\[ V = 3.723875 \, \text{cm}^3 \][/tex]

2. Calculate the Density of the Gold Cube:

The density [tex]\( \rho \)[/tex] of a substance is defined as its mass [tex]\( m \)[/tex] divided by its volume [tex]\( V \)[/tex]:
[tex]\[ \rho = \frac{m}{V} \][/tex]

With the given mass of the gold being 71.9 g and the volume we calculated as 3.723875 cm³, we substitute these values into the formula for density:
[tex]\[ \rho = \frac{71.9 \, \text{g}}{3.723875 \, \text{cm}^3} \][/tex]

Performing this division, we get:
[tex]\[ \rho = 19.307844651069114 \, \text{g/cm}^3 \][/tex]

Thus, the density of the given gold cube is approximately [tex]\( 19.31 \, \text{g/cm}^3 \)[/tex].