Convert g to mg: Molar mass

Question

Suppose it takes 33.69 mL of 0.005123 M EDTA to titrate 25.00 mL of a hard water solution. 

e) Convert g CaCO₃/L calculated in (d) to mg CaCO₃/L. (This is equivalent to ppm.)

Enter your answer as a decimal, NOT in scientific notation. 

Answer 1

e)

33.69/1000 L (0.005123 mol/L) = 0.00017259 mol edta

0.00017259 mol edta = 0.00017259 mol CaCO3

[CaCO3]=0.00017259 mol / (25/1000 L) = 0.0069036 M CaCO3

0.0069036 mol / L (100.086 g / 1 mol) = 0.69095 g/L

0.69095 g/L (1000mg/1g) = 690.95 mg/L = 690.95 ppm