The Polarimeter Tutorial is an interactive animation that provides practice on reading a polarimeter's Vernier scale.
- Adjust the polarimeter dial until both halves have the same orange tint and the word "perfect" appears above the dial.
- Left-click to "freeze" the polarimeter dial.
- Right-click on the image and select "zoom-in" several times to magnify the two scales (see image to the right).
- Note that the "0 mark" on the lower scale is positioned between two integers on the upper scale . . . the 14 and 15.
- The lower of these two numbers (14) is the integer part of the optical rotation reading.
- The decimal place of the optical rotation reading is the mark to the right of the 0 on the lower scale that is perfectly aligned with a mark on the upper scale . . . . note that the ".5" mark on the lower scale is perfectly aligned with the "19" mark on the upper scale.
- The "full" optical rotation reading is 14.5°.
Chem21Labs animations provide a safe environment for learning . . . . students receive "full credit" when they complete the animation correctly - it does not matter how many times they miss part of it and have to start over. This animation can be assigned as a pre-lab activity to prepare students for the lab and again as a post-lab activity to reinforce the lab learning objectives.
The Flash version of this interactive animation is shown below . . . . the updated HTML5-JS version is under construction.