calculate the percent water in CaSO4*2H20
20.9%?
right
To calculate the percent water in CaSO4*2H2O, follow these steps:
1. Start by calculating the molar mass of the entire compound: CaSO4*2H2O.
- The molar mass of CaSO4 (calcium sulfate) is: 40.08 g/mol (Ca) + 32.07 g/mol (S) + (4 * 16.00 g/mol) (O) = 136.14 g/mol.
- The molar mass of 2H2O (water) is: (2 * 1.01 g/mol) (H) + (16.00 g/mol) (O) = 36.02 g/mol.
2. Calculate the molar mass of the water portion only (2H2O):
- Molar mass of 2H2O = 36.02 g/mol.
3. Find the mass of the water portion in CaSO4*2H2O by multiplying the molar mass of 2H2O with the coefficient in front of it (2):
- Mass of 2H2O = (36.02 g/mol) * 2 = 72.04 g.
4. Calculate the percent water in the compound by dividing the mass of the water portion by the molar mass of the entire compound and multiplying by 100:
- Percent water = (Mass of 2H2O / Molar mass of the compound) * 100.
- Percent water = (72.04 g / 172.16 g/mol) * 100 ≈ 41.89%.
Therefore, the percent water in CaSO4*2H2O is approximately 41.89%, not 20.9%.