Epsom salts consist of magnesium sulfate heptahydrate. Write its formula.
a) How many atoms of oxygen are in 5.15g of Epsom salts?
b) How many formula units of the compound are present in 5.15g?
c) How many moles of water molecules are in 5.15 g of Epsom salts?
Thank you so much!!
a) To determine the number of atoms of oxygen in 5.15g of Epsom salts (MgSO4·7H2O), we need to find the molar mass of the compound and use stoichiometry.
The formula for magnesium sulfate heptahydrate is MgSO4·7H2O.
The molar mass of MgSO4 is:
molar mass of Mg = 24.31 g/mol
molar mass of S = 32.07 g/mol
molar mass of O = 16.00 g/mol (x 4 since there are 4 oxygen atoms)
Total = 120.37 g/mol
The molar mass of H2O is:
molar mass of H = 1.01 g/mol (x 2 since there are 2 hydrogen atoms)
molar mass of O = 16.00 g/mol (x 1 since there is 1 oxygen atom)
Total = 18.02 g/mol
Now, calculate the molar mass of the compound MgSO4·7H2O:
molar mass = (molar mass of MgSO4) + (molar mass of 7H2O)
molar mass = 120.37 g/mol + (7 * 18.02 g/mol)
molar mass = 246.47 g/mol
To find the number of moles of the compound in 5.15g:
moles = mass / molar mass
moles = 5.15g / 246.47 g/mol
moles ≈ 0.0209 mol
Since there is a 1:4 ratio between magnesium sulfate and oxygen in the compound, we can calculate the number of oxygen atoms in 5.15g of Epsom salts:
number of oxygen atoms = moles of compound * 4 * Avogadro's number
number of oxygen atoms = 0.0209 mol * 4 * 6.022 x 10^23
number of oxygen atoms ≈ 2.514 x 10^22 atoms
Therefore, there are approximately 2.514 x 10^22 oxygen atoms in 5.15g of Epsom salts.
b) To find how many formula units of the compound are present in 5.15g, we need to use Avogadro's number and the molar mass of the compound.
First, convert the mass of the Epsom salts to moles:
moles = mass / molar mass
moles = 5.15g / 246.47 g/mol
moles ≈ 0.0209 mol
Next, use Avogadro's number to calculate the number of formula units:
number of formula units = moles * Avogadro's number
number of formula units = 0.0209 mol * 6.022 x 10^23
number of formula units ≈ 1.258 x 10^22 formula units
So, there are approximately 1.258 x 10^22 formula units of the compound in 5.15g of Epsom salts.
c) To calculate the number of moles of water molecules in 5.15g of Epsom salts, we need to consider the molar mass of water.
The molar mass of H2O is 18.02 g/mol (calculated in part a).
To find the number of moles of water molecules, we divide the mass of Epsom salts by the molar mass of water:
moles = mass / molar mass
moles = 5.15g / 18.02 g/mol
moles ≈ 0.286 mol
Therefore, there are approximately 0.286 moles of water molecules in 5.15g of Epsom salts.
To answer these questions, we need to use the given information and the molecular formula of Epsom salts.
The molecular formula of Epsom salts, magnesium sulfate heptahydrate, is MgSO4•7H2O. This means that for every one unit of this compound, there is one magnesium ion (Mg2+), one sulfate ion (SO42-), and seven water molecules (H2O).
Now let's proceed to answer the questions:
a) How many atoms of oxygen are in 5.15g of Epsom salts?
To find the number of oxygen atoms, we first need to determine the number of moles of Epsom salts using its molar mass. The molar mass of Epsom salts can be calculated as follows:
Mg = 24.31 g/mol (atomic mass of magnesium)
S = 32.07 g/mol (atomic mass of sulfur)
O = 16.00 g/mol (atomic mass of oxygen)
H = 1.01 g/mol (atomic mass of hydrogen)
Molar mass of MgSO4•7H2O = (24.31 g/mol) + (32.07 g/mol) + (4 × 16.00 g/mol) + (7 × [(2 × 1.01 g/mol) + 16.00 g/mol])
Molar mass of MgSO4•7H2O ≈ 246.48 g/mol
Now, we can calculate the number of moles of Epsom salts in 5.15 g:
Number of moles = mass / molar mass
Number of moles = 5.15 g / 246.48 g/mol
Using a calculator or doing the math, we find that the number of moles of Epsom salts is approximately 0.02 mol.
Since the compound formula contains one oxygen atom in the sulfate ion (SO42-), there are 0.02 mol × (6.022 × 10^23 molecules/mol) × 1 atom = 1.2044 × 10^22 oxygen atoms in 5.15 g of Epsom salts.
b) How many formula units of the compound are present in 5.15g?
To calculate the number of formula units, we will use the Avogadro's number (6.022 × 10^23) and the number of moles of Epsom salts (which we calculated as 0.02 mol).
Number of formula units = number of moles × Avogadro's number
Number of formula units = 0.02 mol × 6.022 × 10^23/mol
Using a calculator or doing the math, we find that there are approximately 1.2044 × 10^22 formula units of Epsom salts in 5.15 g.
c) How many moles of water molecules are in 5.15 g of Epsom salts?
Since there are seven water molecules (H2O) in each formula unit of Epsom salts, we can calculate the number of moles of water molecules using the number of moles of Epsom salts.
Number of moles of water molecules = number of moles of Epsom salts × 7
Number of moles of water molecules = 0.02 mol × 7
Using a calculator or doing the math, we find that there are approximately 0.14 mole of water molecules in 5.15 g of Epsom salts.
Taymis
MgSO4.7H2O
b) 5.15/formula mass = ?
a) moles O atoms = formula units of MgSO4.7H2O x {[4(for 1SO4)+7(for 7H2O)]*6.022E23}= answer from a x 11 x 6.022E23 = ?
c) formula units from a x 7