000333 g fluorescein (332.32 g/mol) is dissolved in 225 ml solution of ethanol. the density of ethanol is 0.785 g/ml. what is the concentration of the solution in molarity (m)? how many ppm? i already

1) Molarity

M = n / V
n: number of moles of solute
V: volume of the solution in liters

n = mass / molar mass = 0.000333 g / 332.32 g / mol =  1*10 ^ - 6 moles

V = 225 ml * 1 liter / 1000 ml = 0.225 liter

M = 10^-6 mol / 0.225 liter = 0.00000444 M

2) ppm

ppm = parts per million

grams of solute: 0.000333 g

grams of solution = volume * density = 225 ml * 0.785 g / ml = 176.625 g

ppm = [0.00033 g / 176.625 g] * 1,000,000 = 1.868 ppm

 

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