Question

Which of the following reaction produce propane as a major product?

• A.

  

• B.

  

• C.

  

• D.

  

Answer 1

The correct option is D

The exact solution is options C and D:

The explanation for the correct options:

Option (C):

• The general reaction of this option is the reduction of the specified alkyl halide

$\mathrm{R}-\mathrm{Cl}\stackrel{\mathrm{Zn},\mathrm{dil}.\mathrm{HCl}}{\to }\mathrm{H}+\mathrm{HClR}-\mathrm{Cl}\stackrel{\mathrm{Zn},\mathrm{dil}.\mathrm{HCl}}{\to }\mathrm{H}+\mathrm{HCl}$

• Once zinc and hydrochloric acid meet, zinc chloride and two hydrogen atoms are produced.
• One of these hydrogen atoms is attached to the halogen group, while the other hydrogen atom takes the place of the halogen atom.

In the reaction given in the option, R− is ${\mathrm{H}}_3\mathrm{C}-{\mathrm{CH}}_2-{\mathrm{CH}}_2-$, thus $\mathrm{R}-\mathrm{H}$ will be propane with the structure ${\mathrm{H}}_3\mathrm{C}-{\mathrm{CH}}_2-{\mathrm{CH}}_3$.

Hence, option C is correct.

Option (D):

• The chemical provided is lowered to generate an alkane and sodium carbonate in this option's process similar. This elicits the following comments:

$\mathrm{R}-\mathrm{COONa}+\mathrm{NaOH}\stackrel{\mathrm{CaO},∆}{\to }\mathrm{R}-\mathrm{H}+{\mathrm{Na}}_2{\mathrm{CO}}_3$
In the reaction given in the option, R− is ${\mathrm{H}}_3\mathrm{C}-{\mathrm{CH}}_2-{\mathrm{CH}}_2-$

Thus, $\mathrm{R}-\mathrm{H}$ will be ${\mathrm{H}}_3\mathrm{C}-{\mathrm{CH}}_2-{\mathrm{CH}}_3$,

which is the structure of propane. Hence, option D is correct.

The explanation for incorrect answers:

Option (A):

The general reaction to this option includes the formation of ${\mathrm{RCOO}}^{-}\mathrm{and}{\mathrm{Na}}^{+}$ ions.

This then leads to the formation of alkyl groups that are free radicals and these two free radicals will combine to form a long alkane.

The general reaction is:
$2\mathrm{R}-\mathrm{COONa}+{\mathrm{H}}_2\mathrm{O}\stackrel{\mathrm{Electrolysis}}{\to }\mathrm{R}+2{\mathrm{CO}}_2$

In the reaction given in the option; thus, R−R will be

${\mathrm{H}}_3\mathrm{C}-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_3$,

which is the structure of hexane. Hence, option A is incorrect.

Option (B):

The stock reaction for this option is to dehalogenation the provided geminal dihalide and release an alkene. Hence propane which is an alkane is not possible to form from this reaction, it is not created to determine the general reaction because the conclusion will be an alkene. Hence option B is incorrect.

Hence, Options C and D are correct.