1) A 3.15 x10^-6 M solution of an iodine solution was measured in a 1.00 cm cell

Question

1) A 3.15 x10^-6 M solution of an iodine solution was measured in a 1.00 cm cell to have an absorbance of 0.267 at 635 nm. A blank solution in this cell had an absorbance of 0.019. What is the concentration of an iodine solution measured in this cell that has an absorption, after blanking the spectrophotometer, of 0.397?

2)Compare the fraction of an atoms in an excited to ground state (N*/N) measured at 254 nm that are formed at the following temperatures: 600K, 1200 K, 2500 K, 4000 K, 6000K and 10,000 K. Assume ground state/excited state degeneracies of 1 and 2, respectively. Does this explain why a flame emission spectrophotometer should be far less sensitive than an ICP spectrometer?

Explanation / Answer

1)

concentration = 3.15 x 10^-6 M

cell length = 1.00 cm

absorbance A = 0.267

A = e C l

0.267 - 0.019 = e x 3.15 x 10^-6 x 1

e = 7.873 x 10^4 M-1 cm-1

e = molar extinction coefficient

blank solution absorbance = 0.397

A = e C l

0.397 - 0.019 = 7.873 x 10^4 x C x 1

C = 4.80 x 10^-6 M

concentration = 4.80 x 10^-6 M

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

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