Aflask contains 0.280 mol of liquid bromine, br2. determine the number of bromine molecules present in the flask.

              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.

law of conservation of matter