What product(s) would you expect from the reaction of 1 mol of 1,3-butadiene and 2 mol of Cl2?
To determine the expected products of a reaction between 1 mol of 1,3-butadiene and 2 mol of Cl2, we need to understand the reaction type and the possible chemical transformations that can take place.
1,3-butadiene is a conjugated diene, and Cl2 is a halogen. Their combination suggests a reaction known as electrophilic addition. In this type of reaction, the pi bond (double bond) of the diene is broken, and new sigma bonds are formed with the electrophilic species (in this case, Cl2).
The reaction progresses in multiple stages, with the formation of several intermediates and transition states. However, to determine the final product(s), we can focus on the initial addition of Cl2 to the diene.
When 1,3-butadiene reacts with Cl2, one Cl2 molecule will add to each of the double bonds in the diene. As a result, two molecules of HCl will be eliminated, forming two new carbon-carbon σ bonds. This reaction is called "1,2-addition" since the chlorine atoms are added to the carbon atoms 1 and 2 of the diene.
The product of the 1,2-addition reaction will result in the formation of a compound called 1,2-dichlorobutane. Since we started with 1 mol of 1,3-butadiene and 2 mol of Cl2, the expected yield of 1,2-dichlorobutane would be 1 mol.
To summarize, the expected product(s) from the reaction of 1 mol of 1,3-butadiene and 2 mol of Cl2 is 1 mol of 1,2-dichlorobutane.