This depends highly on which department you are applying to. If it's chemistry, be ready to do a pre-lab lecture on the topic they supply you with. Make sure not to forget safety in that lecture. Don't make it too long. Stick to what they suggest as a length. Feel free to build in engagement with...
Interview
Clinical
Assistant Professor
New York University
If it's in chemistry, you will be teaching laboratories and recitation sections. Typically, another professor will be leading the lectures. ~50-64 lab students per week. ~100-125 recitation students per week. Typically recitations run 0800-1400 with 15 minute breaks on Fridays.
Day in the Life
Clinical
Assistant Professor
New York University