The forensic technician at a crime scene has just prepared a luminol stock solution by adding 16.0 g of luminol into a total volume of 75.0 mL of H2O. What is the molarity of the stock solution of luminol?

The molarity of the stock solution of luminol is 1.2 M

calculation

step 1: find the moles of luminol using (moles = mass/molar mass) formula

molar mass of Luminol = 177 g/mol

moles is therefore = 16.0 g / 177 g/mol=0.0904 moles

Step 2: find the molarity using (molarity = moles/volume in liters) formula

convert Ml into liters = 75.0/1000 = 0.075 L

molarity is therefore = 0.0904 moles / 0.075 L = 1.2M