Answer : The mass of phosphorous present in sample is 25.8 grams.
Explanation :
First we have to calculate the moles of
.
Molar mass of
= 40 g/mole
![\text{ Moles of }Ca=\frac{\text{ Mass of }Ca}{\text{ Molar mass of }Ca}=\frac{50.0g}{40g/mole}=1.25moles](https://tex.z-dn.net/?f=%5Ctext%7B%20Moles%20of%20%7DCa%3D%5Cfrac%7B%5Ctext%7B%20Mass%20of%20%7DCa%7D%7B%5Ctext%7B%20Molar%20mass%20of%20%7DCa%7D%3D%5Cfrac%7B50.0g%7D%7B40g%2Fmole%7D%3D1.25moles)
Now we have to calculate the moles of phosphorous.
In the molecule
, there are 3 moles of calcium, 2 moles of phosphorous and 8 moles of oxygen.
As, 3 mole of calcium contains 2 moles of phosphorous
So, 1.25 moles of calcium contains
moles of phosphorous
Now we have to calculate the mass of phosphorous.
![\text{ Mass of phosphorous}=\text{ Moles of phosphorous}\times \text{ Molar mass of phosphorous}](https://tex.z-dn.net/?f=%5Ctext%7B%20Mass%20of%20phosphorous%7D%3D%5Ctext%7B%20Moles%20of%20phosphorous%7D%5Ctimes%20%5Ctext%7B%20Molar%20mass%20of%20phosphorous%7D)
Molar mass of phosphorous = 31 g/mole
![\text{ Mass of phosphorous}=(0.833moles)\times (31g/mole)=25.8g](https://tex.z-dn.net/?f=%5Ctext%7B%20Mass%20of%20phosphorous%7D%3D%280.833moles%29%5Ctimes%20%2831g%2Fmole%29%3D25.8g)
Therefore, the mass of phosphorous present in sample is 25.8 grams.