Science Homework Help

1. (a) Write a balanced equation for the coupling reaction of bromoben-

zene on the metal surface to form biphenyl.

2. If you obtained an IR spectrum of triphenylmethanol, compare it with

the spectra in Figure 30.1 and describe the evidence indicating that the

expected reaction has taken place. Interpret your spectrum as com-

pletely as you can.

3. Describe and explain the possible effect on your results of the following

experimental errors or variations. (a) You used solvent-grade (not anhy-

drous) diethyl ether for the reaction in part A. (b) After adding the

bromobenzene solution in part A, you forgot to add anhydrous diethyl

ether to the reaction mixture. (c) You used diethyl ether, rather than

petroleum ether, to remove biphenyl from the crude triphenylmethanol.

6. The reaction of phenylmagnesium bromide with benzophenone to

form the salt of triphenylmethanol is an example of nucleophilic addi-

tion; its reaction with ethyl benzoate to yield the same product involves

nucleophilic substitution followed by a nucleophilic addition step.

Write reasonable mechanisms for both reactions.