0.2 g of Azalea Bush was placed in 20 mls of ethanol and left sitting for a week
ID: 482910 • Letter: 0
Question
0.2 g of Azalea Bush was placed in 20 mls of ethanol and left sitting for a week. I set the wavelength to be used at 658 nm. For absorbance I got 0.5064 and extinction coefficient of 78.5 x 10^3. Using Beers law concentration would be 6.45 x 10^-6. Now how would I calculate mass percent of chlorophyll in my sample?? NEATLY chlorophyll solution, scan from 700-400 nm's. If the peaks the mass percent of chlorophyllin should run use your doesn sample. and to n peaks do a 1:1 in chlorophyll dilution two over inihal for the (ABs) are throughout. 0.22 coefficients calculate the extinction back have Beers Bush to find and using law, you'll Azalea show your Note its absorbance work. Estimate Beers Law you can pick one peak (ABs) and use that. Include units A bc 50 G A 20 (04 Blue 20 mls ethan (concentration) 20 mL mass solute x100 mass percent mass solution mass of chlorophyll ea 3.1 g/mol
Explanation / Answer
For your mass % from chlorophyl:
mass of chlorophil % = mass in smaple / total mass sampe * 100%
total mass sample = 0.2 g of Azalea
note that concentration from Beer's law is molar so:
mol = MV = (6.45*10^-6 mol per liter)(20 mL) ( 1000 mL/1L) = 1.29*10^7 mol of chloophyl
mass of chloophyl = mol*MW = (1.29*10^-7)(893.1 g/mol) = 0.0001152099 g of Chorophyl
so;
mass of chlorophil % = mass in smaple / total mass sampe * 100%
% = 0.0001152099 / 0.2 * 100 = 0.0576%
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