How many oxygen atoms are in 6.70 g of Al2(SO4)3? Express your answer using scientific notation with two decimal places.
moles Al2(SO4)3 = 6.70/molar mass Al2(SO4)3.
Molecules Al2(SO4)3 = moles x 6.022E23.
atoms oxygen = 12 times that
32
To determine the number of oxygen atoms in 6.70 g of Al2(SO4)3, we need to use the molar mass and the Avogadro's number.
First, calculate the molar mass of Al2(SO4)3:
Aluminum (Al) has a molar mass of 26.98 g/mol.
Sulfur (S) has a molar mass of 32.07 g/mol.
Oxygen (O) has a molar mass of 16.00 g/mol.
So, the molar mass of Al2(SO4)3 is:
2(26.98 g/mol) + 3(32.07 g/mol) + 12(16.00 g/mol) = 342.14 g/mol.
Next, calculate the number of moles of Al2(SO4)3 in 6.70 g using the formula:
moles = mass / molar mass.
moles = 6.70 g / 342.14 g/mol ≈ 0.0196 mol.
In Al2(SO4)3, there are 3 oxygen atoms per formula unit. Therefore, multiply the number of moles by the number of oxygen atoms per formula unit to find the total number of oxygen atoms:
0.0196 mol × 3 = 0.0588 mol.
Finally, convert the number of oxygen atoms from moles to scientific notation:
0.0588 mol = 5.88 × 10^-2 mol.
Therefore, there are 5.88 × 10^-2 oxygen atoms in 6.70 g of Al2(SO4)3.
To determine the number of oxygen atoms in 6.70 g of Al2(SO4)3, we'll need to follow a few steps:
Step 1: Calculate the molar mass of Al2(SO4)3.
The molar mass of Al2(SO4)3 can be obtained by summing up the molar masses of its constituent elements:
Al (aluminum) has a molar mass of 26.98 g/mol,
S (sulfur) has a molar mass of 32.06 g/mol,
and O (oxygen) has a molar mass of 16.00 g/mol.
So, the molar mass of Al2(SO4)3 can be calculated as follows:
Molar mass of Al2(SO4)3 = (2 * molar mass of Al) + (3 * molar mass of S) + (12 * molar mass of O)
Molar mass of Al2(SO4)3 = (2 * 26.98 g/mol) + (3 * 32.06 g/mol) + (12 * 16.00 g/mol)
Molar mass of Al2(SO4)3 = 54.97 g/mol + 96.18 g/mol + 192.00 g/mol
Molar mass of Al2(SO4)3 = 343.15 g/mol
Step 2: Convert the given mass to moles using the molar mass.
To convert the given mass of Al2(SO4)3 (6.70 g) to moles, we can use the formula:
Number of moles = Given mass / Molar mass
Number of moles = 6.70 g / 343.15 g/mol
Number of moles = 0.0195 mol
Step 3: Calculate the number of oxygen atoms present using the mole ratio.
From the chemical formula Al2(SO4)3, we can see that there are 12 oxygen atoms in one mole of Al2(SO4)3. Therefore, we can use the mole ratio to calculate the number of oxygen atoms.
Number of oxygen atoms = Number of moles of Al2(SO4)3 * Number of oxygen atoms in one mole
Number of oxygen atoms = 0.0195 mol * (12 atoms)(Avogadro's number)
Step 4: Express the answer in scientific notation.
To express the answer using scientific notation with two decimal places, we need to determine the appropriate power of 10 to use. The Avogadro's number is approximately 6.022 x 10^23.
Number of oxygen atoms = 0.0195 mol * (12 atoms)(6.022 x 10^23 atoms/mol)
Number of oxygen atoms = 0.0195 * 12 * 6.022 x 10^23 atoms
Number of oxygen atoms ≈ 1.405 x 10^23 atoms
Therefore, there are approximately 1.405 x 10^23 oxygen atoms in 6.70 g of Al2(SO4)3.