CHEMISTRY HELP PLEASE

Question

What is the mass of calcium phosphate that can be prepared from 1.98 g of Na3PO4?
Na3PO4(aq)+Ca(OH)2(aq)→Ca3(PO4)2(s)+NaOH(aq)

How to solve please help?

Answer 1

1) Make sure the chemical equation is balanced (same number and type of atoms on both sides of the equation). In this case it is not balanced so you have to find the coefficients in front of each molecule that will balance the equation. The coefficients translate into number of moles of each molecule.

 

2) Once your chemical equation is balanced convert 1.98g of Na₃PO₄ to number of moles of Na₃PO₄ by using its molar mass.

 

3) Once you get the number of moles of Na₃PO₄ from step 2 use the moles proportion shown on the balanced chemical equation to get the number of moles of Ca₃(PO₄)₂. This is a key step here. You need to clearly see what the moles proportions of reactants and products are.

 

4) Then convert the number of moles of Ca₃(PO4)₂ into grams by using its molar mass.

 

 

 

Answer 2

Convert the starting weight of sodium phosphate to moles. From there use the balanced equation to determine the amount of calcium phosphate as the product. 

Your equation should look like this

Grams sodium phosphate × 1/molecular weight of sodium phosphate ×mol calcium phosphate/mol sodium phosphate × molecular weight of calcium phosphate

Make sure your units cancel and you should have your answer. Let me know if you have more questions!