Steve tried to make 3 solutions of calcium phosphate with a concentration of.....?

Question

Steve tried to make 3 solutions of calcium phosphate with a concentration of 2.5 mol/L.
Solution #1 - Mass = 78.3 g Volume= 101.4 mL
Solution #2 - Mass = 76.5 g Volume= 99.8 mL
Solution #3 - Mass = 150.2 g Volume=196.6 mL

*What's the concentration of each of the three solutions?
*Calculate the percent error for each. Which is most accurate & why?

STEPS please don't understand.
Thanks.

Answer 1

Looking at the solubility product of calcium phosphate, there is no way that a solution anywhere near as concentrated as 2.5M could ever be prepared, but that is probably not the point of this rather bad question.

Divide each of the masses given by the Mr of calcium phosphate, and then by the volume given, but converted to litres. Compare the value with 2.5, and work out the percentage difference each time: (2.5 - your value) x 100/2.5