Final answer:
The mass percentage of phosphorous in MgNH4PO4•6H2O is calculated by finding the total molar mass of the compound and dividing the molar mass of phosphorous by this total, then multiplying by 100%.
Step-by-step explanation:
To calculate the mass percentage of phosphorous in MgNH4PO4•6H2O, we need to know the molar mass of the entire compound and the molar mass of phosphorous within it. The formula for mass percent is the mass of the element in the formula divided by the formula mass of the compound multiplied by 100%.
First, calculate the formula mass of the compound:
- Mg = 24.31 amu
- N = 14.01 amu (times 1, because of NH4)
- H = 1.01 amu (times 8, because of NH4 and 6H2O)
- P = 30.97 amu
- O = 16.00 amu (times 4, because of PO4, plus 6 from 6H2O)
Adding these together, we get the formula mass of MgNH4PO4•6H2O. Then, divide the molar mass of phosphorous by this total and multiply by 100% to find the mass percent of phosphorous.