Answer:
17,932.69 g/mol is the molecular weight of the substance.
Explanation:
Using Beer-Lambert's law :
Formula used :
where,
A = absorbance of solution = 1.04
c = concentration of solution =?
l = length of the cell = 1 cm
= molar absorptivity of this solution = 18,650 ![M^{-1} cm^{-1}](https://tex.z-dn.net/?f=M%5E%7B-1%7D%20cm%5E%7B-1%7D)
Now put all the given values in the above formula, we get the molar absorptivity of this solution.
c = ![5.576\times 10^{-5} M](https://tex.z-dn.net/?f=5.576%5Ctimes%2010%5E%7B-5%7D%20M)
![Concentration=\frac{\text{Mass of compound}}{\text{Molecular mass of compound}\times V}](https://tex.z-dn.net/?f=Concentration%3D%5Cfrac%7B%5Ctext%7BMass%20of%20compound%7D%7D%7B%5Ctext%7BMolecular%20mass%20of%20compound%7D%5Ctimes%20V%7D)
V = Volume of the solution in L
Molecular weight of the substance = x
V = 100 mL = 0.1 L
Mass of the substance = 100 mg = 0.1 g
![5.576\times 10^{-5} M=\frac{0.1 g}{x\times 0.1 L}](https://tex.z-dn.net/?f=5.576%5Ctimes%2010%5E%7B-5%7D%20M%3D%5Cfrac%7B0.1%20g%7D%7Bx%5Ctimes%200.1%20L%7D)
x = 17,932.69 g/mol
17,932.69 g/mol is the molecular weight of the substance.