# Help with specific rotation calculations

1. Feb 23, 2010

### oreolrs

Help with specific rotation calculations (urgent)

1. The problem statement, all variables and given/known data

I need help determining a sugar in solution based on the specicific rotation i gained through the required calculation this was done at 589nm

2. Relevant equations

[α] = σ/cl

3. The attempt at a solution
Solution A Solution B Solution C
589nm +2.004 +4.034 -4.434
578nm +2.004 +4.034 -4.438
546nm +2.350 +4.576 -4.995
436nm +3.924 +7.578 -8.195
365nm +6.000 +11.469 -12.280

the calculations done for specific rotation were as followings
[α]λT = σ/cl where σptical rotation measured,
c: concentration w/v - 0.05
λ:wavelength measured at
T:Temperature of the sample when measured – 30.05
L:length of pathway for light – 1cm
Solution A: 589 & 578nm - +2.004/(0.5)(0.1)= 40.08
546nm - +2.350/(0.5)(0.1) = 47
436nm - +3.924/(0.5)(0.1) = 78.48
365nm - +6.000/(0.5)(0.1) = 120
Solution B: 589 & 578nm - +4.034/(0.5)(0.1) = 80.68
546nm - +4.576/(0.5)(0.1) = 91.52
436nm - +7.578/(0.5)(0.1) = 151.56
365nm – +11.469/(0.5)(0.1) =229.38
Solution C: 589nm - -4.434/(0.5)(0.1) = -88.68
578nm - -4.438/(0.5)(0.1) = -88.76
546nm - -4.995/(0.5)(0.1) = -99.9
436nm - -8.195/(0.5)(0.1) = -163.9
365nm - -12.280/(0.5)(0.1)= -245.6
Having been trying to find the specific rotation online or in a crc handbook to determine the type of sugar in each solution.Does anyone know where i can find such information

Last edited: Feb 23, 2010