Calculate the number of atoms in 32.0 g Br2.
I keep getting 1.20 * 10^23 atoms Br2 but my book says i'm wrong.
To calculate the number of atoms in a given amount of a substance, you need to use Avogadro's number and the molar mass of the substance.
1. Start by finding the molar mass of Br2, which is the sum of the atomic masses of two bromine atoms (Br). The atomic mass of bromine is approximately 79.90 g/mol. Therefore, the molar mass of Br2 is 2 * 79.90 g/mol = 159.80 g/mol.
2. Next, divide the given mass of Br2 (32.0 g) by the molar mass to convert grams to moles:
32.0 g / 159.80 g/mol = 0.200 mol
3. Finally, use Avogadro's number (6.022 × 10^23 particles/mol) to calculate the number of atoms:
0.200 mol * 6.022 × 10^23 atoms/mol = 1.20 × 10^23 atoms
Based on the steps above, your calculation of 1.20 × 10^23 atoms of Br2 is indeed correct. It appears that there might be a mistake in your book.
To calculate the number of atoms in 32.0 g of Br2, you need to know the molar mass of Br2 and Avogadro's number.
1. Begin by finding the molar mass of Br2. This can be calculated by adding up the atomic masses of one bromine atom (Br). The atomic mass of bromine (Br) is approximately 79.904 g/mol. Since there are two bromine atoms in one molecule of Br2, you multiply the atomic mass of bromine (79.904 g/mol) by 2 to get the molar mass of Br2:
Molar mass of Br2 = 2 * 79.904 g/mol ≈ 159.808 g/mol
2. Next, you need to convert the given mass (32.0 g) of Br2 to moles. Recall that moles can be calculated by dividing the mass of the substance by its molar mass:
moles of Br2 = mass of Br2 / molar mass of Br2
moles of Br2 = 32.0 g / 159.808 g/mol ≈ 0.200 mol
3. Now, use Avogadro's number, which is approximately 6.022 x 10^23 atoms/mol, to calculate the number of atoms:
number of atoms of Br2 = moles of Br2 * Avogadro's number
number of atoms of Br2 = 0.200 mol * (6.022 x 10^23 atoms/mol)
number of atoms of Br2 ≈ 1.2044 x 10^23 atoms Br2
So, the correct answer for the number of atoms in 32.0 g of Br2 is approximately 1.2044 x 10^23 atoms Br2. Therefore, your answer of 1.20 x 10^23 atoms Br2 is correct, considering rounding to two significant figures.