Answer to Question #126671 in Chemistry for Jell

Question

Calculate the number of atoms present per cubic centimeters of zirconia (ZrO2), which has a density of
6.2 g/cm3

Answer 1

Number of atoms can be calculate by the following formula:

N = n × N_A

where N - number of atoms, n - number of moles, N_A - Avogadro's number (6.022 × 10²³).

Next, number of moles equals:

n = m / Mr

where m - mass, Mr - molecular weight (Mr(ZrO₂) = 123 g/mol)

Finally, mass can be found as:

m = d × V

where d - density, V - volume

As a result, the final formula is:

N = n × N_A = (m / Mr) × N_A = (d × V / Mr) × N_A = (6.2 g/cm³ × 1 cm³ / 123 g/mol) × 6.022 × 10²³ = 3.035 × 10²²

Answer: 3.035 × 10²²