Question

To make the five standard solutions you will need for the Beer's Law Plot, you will first create a stock solution from ( NH 4 ) 3 Fe ( ox ) 3 ⋅ 3 H 2 O . The stock solution is made using 125 mg of ( NH 4 ) 3 Fe ( ox ) 3 ⋅ 3 H 2 O dissolved in deionized (DI) water in volumetric glassware for a total volume of 25 mL. Calculate the concentration of the stock solution.

Answer 1

Concentration of stock solution in g/L = 5.0g/L

Concentration of stock solution in mol/L = 0.00117 mol/L or 0.00117 M

Step-by-step explanation:

Concentration in mol/L = (Concentration in g/L)/(Molar mass)

Mass of (NH₄)₃Fe(ox)₃.3H₂O stock = 125mg = 0.125g

Volume of stock solution required = 25mL = 0.025 L

Concentration in g/L = 0.125/0.025 = 5.0 g/L

Molar Mass of (NH₄)₃Fe(ox)₃.3H₂O = (NH₄)₃Fe(C₂O₄)₃.3H₂O = 428.0632 g/mol

Concentration in mol/L = 5/428.0632 = 0.00117 mol/L = 0.00117 M

Hope this helps!!!