Respuesta :
Answer:
[tex]7.0575\times 10^{-6} M[/tex] is the molar concentration of the solution.
5.759 mg of crystal violet was dissolved to prepare the 2.00 mL sample that was measured in the cuvette.
Concentration of the solution in ppm is 2,879.31.
Explanation:
Using Beer-Lambert's law :
Formula used :
[tex]A=\epsilon \times C\times l[/tex]
where,
A = absorbance of solution
C = concentration of solution
[tex]\epsilon [/tex] = The molar absorptivity coefficient
We have :
A = 0.614 , l = 1.0 cm , C= ?
[tex]\epsilon =87,000 M^{-1} cm^{-1} [/tex]
[tex]C=\frac{A}{\epsilon l}=\frac{0.614 }{87,000 M^{-1} cm^{-1}\times 1 cm}[/tex]
[tex]C=7.0575\times 10^{-6} M[/tex]
[tex]7.0575\times 10^{-6} M[/tex] is the molar concentration of the solution.
[tex]Moles (n)=Molarity(M)\times Volume (L)[/tex]
Moles of crystal violet = n
Volume of crystal violet solution = 2.00 mL = 0.002 L
Molarity of the crystal violet = [tex]C=7.0575\times 10^{-6} M[/tex]
[tex]n=7.0575\times 10^{-6} M\times 0.002 L=1.4115\times 10^{-5} mol[/tex]
Mass of [tex]1.4115\times 10^{-5} mol[/tex] of crystal violet:
[tex]1.4115\times 10^{-5} mol\times 407.98 g/mol=0.005759 g[/tex]
0.005759 g = 5.759 mg (1 g = 1000 mg)
5.759 mg of crystal violet was dissolved to prepare the 2.00 mL sample that was measured in the cuvette.
[tex]ppm = \frac{\text{mass of compound (mg)}}{\text{volume of solution}L}[/tex]
Mass of crystal violet = 5.759 mg
Volume of solution= 2 mL = 0.002 L
Concentration of the solution in ppm:
[tex]=\frac{5.759 mg}{0.002 L}=2879.31 ppm[/tex]
