CHEM323 - Abstracts: In this experiment, the...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
In this experiment, the spectrophotometer was used to determine the concentration of chromium (III) and cobalt (II) in an unknown mixture. The k Co 510 , k Co 575 , k Cr 510 and k Cr 575 were 4.23, 0.5053, 5.5429 and 12.667 respectively. Also the percentage errors between A measured and A theoretically were 3.26 % and 10.34 % for A 510 (mixture) and A 575 (mixture). The concentrations of the chromium (III) and cobalt (II) in an unknown mixture #2 were 0.017 M and 0.098 M. Objective: To determine the concentrations of the two components chromium (III) and cobalt (II) in an unknown mixture using beer’s law and spectrophotometer . Theory: When a solution of two colored substances is prepared, the presence of the second component often causes a change to occur in the light-absorbing properties of the first component. With such solutions the absorbance by the component is not additive, which precludes a simple quantitative determination of their concentration. According to Beer's law, the proportionality relationship between the absorbance of a substance and its concentration is : A = ЄbC A = kC Where, k is the absorptive constant . For Beer's law plot of A vs. C, k is the slope of the line . For a solution that contains two light-absorbing components (A and B) whose absorbances are additive, the total absorbance of the solution at some wavelengths λ1 and λ2 is the some of the individual absorbencies. That is,
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/24/2011 for the course CHEM 323 taught by Professor Basimali during the Fall '09 term at King Fahd University of Petroleum & Minerals.

Page1 / 7

CHEM323 - Abstracts: In this experiment, the...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online