Question

How many formula units are there in 325 grams PbO2?

Answer 1

Answer:

There are approximately 8.183 × 10²³ units of PbO₂ in 325 grams of PbO₂

Explanation:

The given mass of PbO₂ = 325 grams

The molar mass of PbO₂ = 239.2 g/mol

The number of moles of PbO₂ in 325 grams of PbO₂ is given by the formula for the number of moles of a chemical compound in a given sample of the compound as follows;

$The \ number \ of \ moles, n = \dfrac{Mass \ of \ the \ substance}{Molar \ mass \ of \ the \ substance}$

For the given PbO₂ compound, in the question, we have;

$The \ number \ of \ moles, n = \dfrac{325 \ g}{239.2 \ g/mole} \approx 1.36 \ moles$

The number of units of PbO₂ in one mole is given by the Avogadro's number as follows;

The number of units of PbO₂ per mole = 6.023 × 10²³ units

The number of units of PbO₂, $U_{PbO_2}$ in 1.36 mole of PbO₂ is therefore;

$U_{PbO_2}$  = 1.36 × 6.023 × 10²³ units ≈ 8.183 × 10²³ units of PbO₂

The number of units of PbO₂, in 1.36 mole of PbO₂ ≈ 8.183 × 10²³ units.