Question

The density of aluminum is 2.70 g/cm^3? How many aluminum atoms are in a block of aluminum

with a volume of 114.2 cm^3?

Answer 1

68.77×10²³ atoms

Step-by-step explanation:

Given data:

Density of Al = 2.70 g/cm³

Volume of Al block = 114.2 cm³

Number of atoms of Al = ?

Solution:

First of all we will determine the mass of Al.

D = m/v

2.70 g/cm³ = m/114.2 cm³

m = 2.70 g/cm³ × 114.2 cm³

m = 308.34 g

Now we will calculate the number of moles of Al.

Number of moles = mass/molar mass

Number of moles = 308.34 g/27 g/mol

Number of moles = 11.42 mol

Number of atoms of Al:

1 mole = 6.022×10²³ atoms

11.42 mol × 6.022×10²³ atoms/1 mol

68.77×10²³ atoms