# Will table sugar twist polarized light?

Chemically, table sugar is sucrose, whose molecule is basically a unit of glucose and a unit of fructose connected together. To know the expected amount of rotation of polarization for a given substance, see the table of specific rotations.

In particular, for D-glucose specific rotation is $$+52.7°\,\mathrm{dm}^{-1}\,\mathrm{cm}^3\,\mathrm{g}^{-1}$$, while for D-sucrose it's $$+66.37°\,\mathrm{dm}^{-1}\,\mathrm{cm}^3\,\mathrm{g}^{-1}$$, which is actually even larger than that of D-glucose. So yes, you should be able to succeed with the experiment using table sugar instead of glucose.

I have successfully done this demonstration in my classes using table sugar. I place a polarizer on an old-fashioned overhead projector, hold a crossed polarizer above it to block the light, and then insert a beaker of sugar solution between the two. I usually use a solution of 1:1 sugar-to-water (by volume), basically a "simple syrup"; and I use a column depth of about 10 cm or so.

If I remember correctly, the transmitted light has a distinct bluish color when you do this, which I assume is due to the frequency dependence of the specific rotation.

Yes, I helped my daughter do this demonstration for her sixth grade science project. She used plain table sugar and a laser pointer as the light source. Having a monochromatic source makes it a little clearer. If you have different color laser pointers it would be interesting to demonstrate wavelength dependence.