Question

The forensic technician at a crime scene has just prepared a luminol stock solution by adding 15.0 gg of luminol into a total volume of 75.0 mLmL of H2OH2O. What is the molarity of the stock solution of luminol? Express your answer with the appropriate units.

Answer 1

1.13 M

Step-by-step explanation:

Given data

• Mass of luminol (solute): 15.0 g

• Volume of solution = volume of water = 75.0 mL = 0.0750 L

• Molar mass of luminol: 177.16 g/mol

The molarity of the stock solution of luminol is:

M = mass of solute / molar mass of solute × liters of solution

M = 15.0 g / 177.16 g/mol × 0.0750 L

M = 1.13 M