A flask containing the molecule shown above, an enantiomers of 2,2'-dimethylbiphenyl, exhibits optical activity at room temperature. If we heat it to 200C for 1 hr and allow it to cool to room temperature, we find that the sample has become optically inactive. Explain this observation by answering the following questions:
1) What does it mean to be optically active or optically inactive?
2) What features of a molecule or a flask full of molecules would make them optically active or inactive?
3) Is the molecule chiral or achiral? Why?
4) What would heating the molecule do to it (hint: no bonds are broken and no reaction takes place)?
5) How did the sample become optically inactive????
6) Can you draw the other enantiomer at room temperature?