number of 32.0 grams Br^2
number of what? number of moles? moles = gram/molar mass.
To calculate the number of moles of a substance, you need to use its molar mass. The molar mass of a compound is the sum of the atomic masses of all the atoms in a single molecule of that compound.
To determine the molar mass of Br2 (diatomic bromine), we need to know the atomic mass of bromine.
The atomic mass of bromine (Br) is approximately 79.904 grams per mole (g/mol). Since the molecule of Br2 contains two bromine atoms, we multiply the atomic mass by 2 to find the molar mass of Br2.
Molar mass of Br2 = 2 * 79.904 g/mol = 159.808 g/mol
Now that we have the molar mass of Br2, we can calculate the number of moles in 32.0 grams.
Number of moles = Mass of the substance / Molar mass
Number of moles of Br2 = 32.0 g / 159.808 g/mol
Calculating this:
Number of moles of Br2 ≈ 0.2002 mol
Therefore, there are approximately 0.2002 moles of Br2 in a 32.0 grams sample.