Question

1. Determine the volume of the aluminum foil using the density of foil.

Volume = mass (g) x density g/cm3

Volume = 4.29 g/ 2.70 g/cm3

Volume= 1.59 cm3

2. Determine the volume of one atom of aluminum.

3. Determine the number of atoms of aluminum in the foil sample.

4. Determine the moles of aluminum.

5. Calculate Avogadro’s number.

Answer 1

Ans. Given,

Mass of aluminum foil = 4.29 g

Density of aluminum foil = 2.70 g/ cm³

Volume of aluminum foil = Mass / Density = 4.29 g / (2.70 g/ cm³) = 1.59 cm³

#2. Moles of Al in sample = Mass/ Molar mass

                                    = 4.29 g/ (26.89 g/ mol)

                                    = 0.15842 mol

Number of Al- atoms = Number of moles x Avogadro number

                                    = 0.15842 mol x (6.022 x 10²³ atom/ mol)

                                    = 9.54024 x 10²² atoms.

Volume of one Al-atom = Volume of Al-foil/ Number of atoms in it

                                    = 1.59 cm³ / (9.54024 x 10²² atoms)

                                    = 1.67 x 10^-23 cm³/ atom

#3. Number of Al-atoms = 9.54024 x 10²² atoms           ; [see #2]

#4. Moles of Al = 0.15842 mol                                          ; [see #2]

#5. Avogadro number = Number of Al-atoms/ Moles of Al

                                    = 9.54 x 10²² atoms / 0.16 mol

                                    = 6.022 x 10²³ atoms/ mol