Calculate the percent by mass of water in magnesium sulfate heptahydrdrate (MgSO4-7H2O)
(molas mass H2O x 7/(molar mass of the MnSO4.7H2O)*100
Swag
To calculate the percent by mass of water in magnesium sulfate heptahydrate (MgSO4-7H2O), we need to determine the mass of water and the total mass of the compound.
Step 1: Determine the molar mass of magnesium sulfate heptahydrate (MgSO4-7H2O).
- The molar mass of magnesium (Mg) is 24.31 g/mol.
- The molar mass of sulfur (S) is 32.06 g/mol.
- The molar mass of oxygen (O) is 16.00 g/mol.
- The molar mass of hydrogen (H) is 1.01 g/mol.
- Since there are 7 water molecules (H2O), we multiply the molar mass of water by 7.
- Add up the molar masses of all the elements in the compound to find the molar mass of MgSO4-7H2O.
Step 2: Calculate the mass of water.
- Since the molar mass of water (H2O) is 18.02 g/mol, multiply this by the total number of water molecules (7) to get the mass of water.
Step 3: Calculate the total mass of the compound (MgSO4-7H2O).
- This can be calculated by adding the molar mass of MgSO4 to the mass of water calculated in step 2.
Step 4: Calculate the percent by mass of water.
- Divide the mass of water (from step 2) by the total mass of the compound (from step 3).
- Multiply the result by 100 to find the percentage.
Let's calculate it:
Step 1: Molar mass of MgSO4:
- Mg: 1 * 24.31 g/mol = 24.31 g/mol
- S: 1 * 32.06 g/mol = 32.06 g/mol
- O: 4 * 16.00 g/mol = 64.00 g/mol
Total: 120.37 g/mol
Molar mass of H2O: 18.02 g/mol
Molar mass of 7H2O: 7 * 18.02 g/mol = 126.14 g/mol
Molar mass of MgSO4-7H2O:
120.37 g/mol + 126.14 g/mol = 246.51 g/mol
Step 2: Mass of water:
18.02 g/mol * 7 = 126.14 g
Step 3: Total mass of the compound:
120.37 g/mol + 126.14 g = 246.51 g
Step 4: Percent by mass of water:
(126.14 g / 246.51 g) * 100 = 51.17%
Therefore, the percent by mass of water in magnesium sulfate heptahydrate (MgSO4-7H2O) is approximately 51.17%.