Answer:
1.68 × 10²³ Molecules
Explanation:
As we know that 1 mole of any substance contains exactly 6.022 × 10²³ particles which is also called as Avogadro's Number. So in order to calculate the number of particles (molecules) contained by 0.280 moles of Br₂, we will use following relation,
Moles = Number of Molecules ÷ 6.022 × 10²³ Molecules.mol⁻¹
Solving for Number of Molecules,
Number of Molecules = Moles × 6.022 × 10²³ Molecules.mol⁻¹
Putting values,
Number of Molecules = 0.280 mol × 6.022 × 10²³ Molecules.mol⁻¹
Number of Molecules = 1.68 × 10²³ Molecules
Hence,
There are 1.68 × 10²³ Molecules present in 0.280 moles of Br₂.