Question

Gas chromatography and polarimetry experiment.

What is the goal of a polarimetry lab? What was the starting material? Indicate the chiral carbon. What was the principle of polarimetry? What was the conclusion? Using the following data, show the entire process of calculation. The angle of rotation was 1.55, the concentration of Limonene was 0.027 g/ml, and the light path was 1 dm.

Answer 1

1. Polarimetry is a sensitive and non-destructive technique used for measuring the optical activity of inorganic and organic chiral compounds

2. In polarimetry sucrose solutions are used to check the linearilty of the scale

3. Principle: Chiral compounds has the ability to rotate the plane polarized towards right or left side. The direction of rotation of plane polarized light by the chiral samples depends on the spatial arrangement of atoms around the chiral center and the magnitude of rotation depends on the amount of sample in the solution

The angle of rotation of light depends on temperature wavelength of light used, path length and concentration of sample

Ex: (R)-2-butanol has the specific rotation of -13.52 o at 25 C and its enantiomer (S)-2-butanol shows +13.52 o

4. From given data, specific rotation can be calculated as

degrees