a sample of Ca3(PO4)2 contains 3.1g phosphorus then the weight of Ca in the sample is ?
In order to find the weight of Ca in the sample, we need to determine the molar mass of Ca3(PO4)2 and then calculate the weight of Ca.
The molar mass of Ca3(PO4)2 can be calculated by summing the atomic masses of its constituent atoms. Here are the atomic masses of the elements involved:
- Calcium (Ca): 40.08 g/mol
- Phosphorus (P): 30.97 g/mol
- Oxygen (O): 16.00 g/mol
Now, let's calculate the molar mass of Ca3(PO4)2:
Molar mass of Ca3(PO4)2 = (3 * Ca) + (2 * P) + (8 * O)
= (3 * 40.08) + (2 * 30.97) + (8 * 16.00)
= 120.24 + 61.94 + 128.00
= 310.18 g/mol
Given that the sample contains 3.1g of phosphorus (P), we can use this information to calculate the weight of calcium (Ca) using the mole ratio of Ca3(PO4)2.
Moles of P = Mass of P / Molar mass of P
= 3.1 g / 30.97 g/mol
= 0.100 mol
According to the chemical formula, 1 mole of Ca3(PO4)2 contains 3 moles of Ca. Therefore, the moles of Ca in the sample are equal to the moles of P.
Moles of Ca = Moles of P
= 0.100 mol
Finally, we can calculate the weight of Ca:
Weight of Ca = Moles of Ca * Molar mass of Ca
= 0.100 mol * 40.08 g/mol
= 4.008 g
Therefore, the weight of Ca in the sample is approximately 4.008 grams.
To find the weight of calcium (Ca) in the sample of Ca3(PO4)2, we need to calculate the molar mass of calcium phosphate (Ca3(PO4)2) and then use the given weight of phosphorus to determine the weight of calcium.
Step 1: Find the molar mass of Ca3(PO4)2.
The molar mass of Ca is 40.08 g/mol, the molar mass of P is 30.97 g/mol, and the molar mass of O is 16.00 g/mol.
Calculating the molar mass of Ca3(PO4)2:
(3 * 40.08 g/mol) + (2 * (30.97 g/mol + 4 * 16.00 g/mol))
= 120.24 g/mol + (2 * (30.97 g/mol + 64.00 g/mol))
= 120.24 g/mol + (2 * 94.97 g/mol)
= 120.24 g/mol + 189.94 g/mol
= 310.18 g/mol
Therefore, the molar mass of Ca3(PO4)2 is 310.18 g/mol.
Step 2: Use the molar mass to find the weight of calcium.
Given that the weight of phosphorus (P) is 3.1 g, we can use the molar ratio between phosphorus and calcium phosphate to determine the weight of calcium.
The molecular formula of calcium phosphate shows that there are 2 moles of phosphorus atoms for every 3 moles of calcium atoms (Ca3(PO4)2).
Using this ratio, we can set up the following proportion:
2 mol P / 3 mol Ca = 3.1 g P / x g Ca
Cross-multiplying gives us:
(2 mol P) * (x g Ca) = (3 mol Ca) * (3.1 g P)
Simplifying, we get:
2x g Ca = 9.3 g P
Finally, divide both sides of the equation by 2 to find the weight of calcium:
x g Ca = 9.3 g P / 2
Therefore, the weight of calcium (Ca) in the sample is 4.65 g.
3.1 g P is how many moles P? moles = g/molar mass.
There are two moles P atoms per mole Ca3(PO4)2 and 3 moles Ca atoms per mole Ca3(PO4)2, then 1/2 P moles will be moles Ca3(PO4)2 and 3x that value will be moles Ca atoms.