What is the mass of 4.00 mol of Ca3(PO4)2

Question

What is the mass of 4.00 mol of Ca₃(PO₄)₂

Answer 1

In order to determine the mass in this scenario you want to calculate the molar mass of the compound and then multiply by the given number of moles.

In this case for the compound Ca₃(PO₄)₂, you can find the molar mass by taking

3(Ca) + 2(P) + 8(O)

=3(40.08) + 2(30.97) + 8(16)

=120.24 + 61.94 + 128

=310.18

so the molar mass is 310.18 g/mol

Finally then you can calculate the Final Mass by multiplying by the moles

Mass = Moles x Molar Mass

Mass = 4.00 mol x 310.18 g/mol

Mass = 1240.72 g

meaning that the end mass here is around 1241 grams

Answer 2

The molecular weight of a substance is the mass in grams of a mole of the substance.  Find the molecular weight of Ca3(PO4)2, multiply by 4, and you will have the mass of 4 moles of Ca3(PO4)2.

 

Atomic weights:

 

Ca - 40.08

P   - 30.97

O  - 16.00

 

Molecular weight of Ca3(PO4)2 = 3(40.08) + 2[30.97 + 4(16.00)] = 310.18

 

So the mass of 4.00 mols is 4(310.18) g = 1240.72 g