The potential difference between two points in an electric circuit is the work done when a coulomb of charge passes between the points. You can calculate the size of a potential difference using this equation: V = W Ã· Q. 1  V is the potential difference in volts, V. 2  W is the work done (energy transferred) in joules, J.
Thanks for you help. Yikes, now you got me thinking! I went and my bottle of wilton vanilla and sure enough, it was like I went to the medicine cabinet and opened the bottle of rubbing alcohol! Extract is about 35% or so alcohol, so it may smell like alcohol - but the primary aroma should be vanilla.
Although not a perfect test, your nose is usually the most reliable instrument to tell if your vanilla extract has gone bad. If vanilla extract has gone bad, the pleasant aroma will be gone and with it much of the vanilla flavor.