Question

Pre-Laboratory Assignment 1. What safety precautions must be observed when using (a) pyridinium tribromide? (b) acetic acid? 2. Calculate the theoretical yield for the bromination of both stilbenes and cinamic acid, assuming the presence of excess pyridinium tribromide. Note the theoretical yields here and in your laboratory notebook 3. Draw the mechanism, including the intermediate bromonium ion, generated in the bromination of trans-2-butene. 4. (a) Look up and draw structures for cinnamic acid, cis-stilbene, and trans-stilbene. (b) Predict the relative stereochemistry of each product and draw the predicted structures.

Answer 1

a) Pyridinium tribromide Property Pyridinium tribromide has corrosive, which means that it will damage other substances with which it comes into contact. It can also irritates the eyes and causes fears to flow skin irritation , blindness - Safety Precautions - • One must use tume hood while using the Pyridinium tribromide. o) one must avoid skin contact of fumes contact with eyes. .) one must wear goggles and gloves . .) one must be provided with protection . from fire. .) one must wear mask over mouth of nose

b) Acetu acid Acetic acid is a weak acid but it has corrosive Property and causes irritation to the eyes and skin . It can also damage the internal organs if it is ingested or if inhaled. E Safety Precautions . o one must use the tume hood at the time of using it. Fume hood is a Ventilated work space it exhaust harmful, dangerous fumes & Particles o) One must wear goggles & gloves of one must wear makk over mouth & nose one must avoid skin & eye contact.