A 120.0-gram sample of Cr2(SO4) contains how many sulfur atoms
figure how many moles. Then, each mole contains Avogadro's Number of sulfur atoms.
Let me point out that you probably meant Cr2(SO4)3
To determine the number of sulfur atoms in a 120.0-gram sample of Cr2(SO4), we need to use the Avogadro's number and the molar mass of Cr2(SO4).
1. Calculate the molar mass of Cr2(SO4):
- The molar mass of chromium (Cr) is 52 grams/mol.
- The molar mass of sulfur (S) is 32 grams/mol.
- The molar mass of oxygen (O) is 16 grams/mol.
So, the molar mass of Cr2(SO4) is:
(2 * molar mass of Cr) + (1 * molar mass of S) + (4 * molar mass of O)
= (2 * 52 g/mol) + (1 * 32 g/mol) + (4 * 16 g/mol)
= 104 g/mol + 32 g/mol + 64 g/mol
= 200 g/mol
2. Calculate the number of moles in the given sample:
Number of moles = mass / molar mass
Number of moles = 120.0 g / 200 g/mol
Number of moles = 0.6 mol
3. Since Cr2(SO4) has a 1:1 ratio of sulfur atoms to the compound, there are 0.6 mol of sulfur atoms in the sample.
4. Use Avogadro's number to find the number of sulfur atoms:
Number of sulfur atoms = number of moles * Avogadro's number
Number of sulfur atoms = 0.6 mol * (6.022 * 10^23 atoms/mol)
Number of sulfur atoms = 3.6132 * 10^23 sulfur atoms
Therefore, a 120.0-gram sample of Cr2(SO4) contains 3.6132 * 10^23 sulfur atoms.
To determine the number of sulfur atoms in a 120.0-gram sample of Cr2(SO4), we need to follow a series of steps.
Step 1: Determine the molar mass of Cr2(SO4)
To calculate the molar mass of Cr2(SO4), we need to add up the atomic masses of all the atoms present in one formula unit.
- The atomic mass of chromium (Cr) is 52.0 g/mol, and since Cr2 is present, the total mass of chromium in the formula unit is 2 * 52.0 = 104.0 g/mol.
- The atomic mass of sulfur (S) is 32.06 g/mol, and since there are four sulfur atoms in the formula unit, the total mass of sulfur in the formula unit is 4 * 32.06 = 128.24 g/mol.
- The atomic mass of oxygen (O) is 16.00 g/mol, and since there are four oxygen atoms in the formula unit, the total mass of oxygen in the formula unit is 4 * 16.00 = 64.00 g/mol.
Thus, the molar mass of Cr2(SO4) is 104.0 + 128.24 + 64.00 = 296.24 g/mol.
Step 2: Calculate the number of moles
To calculate the number of moles, we need to divide the given sample mass (120.0 grams) by the molar mass of Cr2(SO4) obtained in step 1:
Number of moles = Sample mass / Molar mass
= 120.0 g / 296.24 g/mol
Step 3: Calculate the number of sulfur atoms
Since there are four sulfur atoms in one formula unit of Cr2(SO4), we can multiply the number of moles of Cr2(SO4) obtained in step 2 by the Avogadro's number to find the number of sulfur atoms:
Number of sulfur atoms = Number of moles * Avogadro's number
= (120.0 g / 296.24 g/mol) * 6.022 × 10^23 atoms/mol
By performing the calculations, you will get the final answer to the question, which is the number of sulfur atoms in the given sample of Cr2(SO4).