copper II sulfate solution whose concentration you know Construct a calibration graph Find the concentration of unknown copper II sulfate solutions Colorimetry Colorimetry Step 1 ID: 802222
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Slide1
Objectives:Make up a standard copper (II) sulfate solution, whose concentration you know.Construct a calibration graph.Find the concentration of unknown copper (II) sulfate solutions.
Colorimetry
Slide2Colorimetry
Slide3Step 1: Make a standard CuSO4 solution
Slide4Weighing the solidWeigh 6.24g of CuSO4.5H2O, add the powder to a beaker and dissolve in 50cm
3 water.
Colorimetry
Slide5Standard solutionTransfer solution to a 100cm3 volumetric flask and add more distilled water until the meniscus sits on the graduation line to make your 0.25M solution.
Colorimetry
Slide6Step 2: Colorimetry experiment
Slide7Colorimetry experimentColoured solutions absorb light that has passed through a filter. Darker solutions absorb more light.Turn on the colorimeter, ensure the yellow filter has been selected.Select ‘abs’ then place a cuvette filled with distilled water into the colorimeter. Press ‘R’ for reference. Add your 0.25M copper sulfate and press ‘T’ to record absorbance.
Repeat with 0.20M. 0.15M, ).10M and 0.05M solutions.
Colorimetry
Slide8Calibration graphPlot a calibration graph and find the unknown concentration of the solutions.The technician said that: - unknown A/unknown 1 was 0.125 M - unknown B/unknown 2 was 0.075 MColorimetry
Concentration (moldm
-3
)
Absorbanc
e
x
x
x
x
x
x
Unknown 2
Unknown 1
0.125M
0.075M
Slide9ColorimetryA very good quick video on the method:https://www.youtube.com/watch?v=CxxGiqaBEPshttps://www.youtube.com/watch?v=yrXZXGbg9KIA comparison of titrations and colorimetry:http://education.seattlepi.com/titration-different-colorimetry-4356.htmlColorimetry