Week 4 -Spectroscopic analysis of aspirin re-Lab Questions If 25% of the light p

Question

Week 4 -Spectroscopic analysis of aspirin re-Lab Questions If 25% of the light passing through a sample is Transmitted, what is the Absorbance A of the solution? B?"complexes with Thiourea to form a colored Complex which Absorbs light at = 470 nm with an Extinction Coefficient of = 9320 M-1cm-1. What is the concentration of the complex in a solution that has a measured Absorbance A-0.265 in 1.00 cm cell. 3. When comparing the absorbance of two solutions of the same substance but of different concentrations. Solution A has an absorbance greater than that of the reference solution. How would you conclude about the concentration of solution A compared with the reference solution?

Explanation / Answer

1. Absorbance = 2 - log(%T)

with,

%T = 25%

we get,

absorbance = 2 - log(25) = 0.602

2. concentration of complex in solution = absorbance/molar absorptivity x path length

with,

molar absorptivity = 9320 M-1.cm-1

path length = 1 cm

absorbance = 0.265

we get,

concentration of complex = 0.265/9320 x 1 = 2.84 x 10^-5 M

3. A solution of higher concentration would absorbs more light than a solution of lower concentration. If we were to take absorbance measurement of a reference blank solution and compare it with a solution of substance of unknown concentration, we would get higher absorbance value for unknown concentration solution, confirming this has greater amount of substanvce dissolved in it.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.