This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Nick Frazier Quantitative analysis and Beer's law 1. The true molarity of our stock solution : Actual mass of CoSO4 = 5.622g CoSO4 V= 100 mL M= 1mol CoSO4 x 5.622 g x 1 mL = 0.2 M CoSO4 281.10g .01 L 2. Sample 1 2 3 4 3. Average Absorbance 1.053 .872 .645 .431 .214 .778 Dilution concentration .16 M .12 M .08 M .04 M M1xV1=M2xV2 0.2(20mL)=M2(25mL) M2= .16 M Stock 1 2 3 4 Unknown A 4. 0.25 0.2 0.15 0.1 CoSO4 solution 0.05 concentration 0 (M) 0 0.2 0.4 0.6 0.8 1 1.2 Series1 Average Absorbance The significance of the slope of this line is it shows absorbance versus the concentration. Through this we can find the concentration of the unknown. 5. The concentration of the unknown is approximately .145 M. I found this by using the plot and finding .778 on the average absorbance and then finding the corresponding concentration. 6. The experimental results are quite precise and accurate. We took more than one measurement so that error would be minimal. The more trials you take the more accurate your results will be. 7. Possible error may have occurred if we did not wipe off the tube well enough before putting it into the spectrophotometer. Other experimental error could have occurred while measuring out the solutions. ...
View Full Document
- Spring '08