Question

The following questions were not following an experiment. They are able to be answered without more information.

2. In free-raducal halogenation reaction, one can predict the relative amounts of the possible products using a simple equation: (probability factor to form a given product)x(reactivity factor)=relative amount of that product For example: consider the monochlorination of propane. Two products are possible: 1-chloropropane and 2- chloropropane. Replacing any of the six 1 hydrogen gives 1- chloropropane and replacing either of the two 2 hydrogens will give 2- chloropropane. Therefore, the probability factor for forming 1- chloropropane is 6 and the probability factor forming 2- chloropropane is 2. The relative reactivity factors for chlorine are, for 1, 2, and 3 C-H bonds, 1.0, 3.5, and 5.0, respectively. If butane is subjected to free-radical chlorination, what would be the relative ratios of 1- chlorobutane and 2- chlorobutane?

3. Calculate the relative product ratios for the free-radical bromination of butane. The reactivity factor for 1, 2, and 3 C-H bonds with bromine are 1.0, 82, and 1600, respectively.

4. Calculate the relative ratios of products for the monochlorination of 2-methylpropane. Remember to determine how many ways a particular product could be produced (how many different hydrogens could be replaced to give the same product). Hint: Drawing out the starting material and the possible products may be helpful.

5. Calculate the relative ratios of products for the monochlorination of 2,4-dimethylpropane. Remember to determine how many ways a particular product could be produced (how many different hydrogens could be replaced to give the same product). Hint: Drawing out the starting material and the possible products may be helpful.

Answer 1

2.Butane is subjected to free-radical chlorination, what would be the relative ratios of 1- chlorobutane and 2- chlorobutane?​

Relative amount of that product = (probability factor to form a given product) x (reactivity factor)

The probability factor for forming 1- chlorobutane is 6 and the probability factor forming 2- chlorobutane is 4.

The relative reactivity factors for chlorine are, for R-CH₃(primary), R-CH₂-R(secondary), and R₃-CH(tertiary) bonds, 1.0, 3.5, and 5.0, respectively

Relative amount of 1-chlorobutane = 6 x 1.0 = 6

Relative amount of 2-chlorobutane = 4 x 3.5 = 14

Relative ratio of 1- chlorobutane and 2- chlorobutane = 6:14 = 30:70

3. Calculate the relative product ratios for the free-radical bromination of butane.

The reactivity factor for 1, 2, and 3 C-H bonds with bromine are 1.0, 82, and 1600, respectively.

Relative amount of 1-bromobutane = 6 x 1.0 = 6

Relative amount of 2-bromobutane = 4 x 82 = 328

Relative ratio of 1-bromobutane and 2-bromobutane = 6:328

4. Calculate the relative ratios of products for the monochlorination of 2-methylpropane.

Relative amount of 1-chloro-2-methylpropane =9 x 1.0 = 9

Relative amount of 2-chloro-2-methylpropane = 1 x 5.0 = 5

Relative ratio = 9:5

5.Calculate the relative ratios of products for the monochlorination of 2,4-dimethylpropane.

Relative amount of 1-chloro-2,4-dimethylpropane =12 x 1.0 = 12