In an attempt to prepare n−propylbenzene, a chemist alkylated benzene with 1−chloropropane and aluminum chloride. however, two isomeric hydrocarbons were obtained in a ratio of 2: 1, the desired n−propylbenzene being the minor component. what do you think was the major product? how did it arise?

2-Phenylpropane (Cumene)

Explanation:

Famous Friedel Craft Alkylation.

Aluminum Chloride grasped the 1-chloropropane forming an intermediate product composed of Aluminum tetrachloride and n-propylcation. It is well understood that primary carbocations are unstable and therefore undergo hydrogen shifting to attain stability. n-Propylcarbocation undergone hydrogen shifting, forming isopropylcarbocation which reacted with benzene forming 2-Phenylpropane as the major product and HCl as a byproduct.

AlCl3 + CH3CH2CH2Cl --> AlCl4-   +   CH3CH2CH2+

CH3CH2CH2+  ---> CH3CH(+)CH3

C6H6 + CH3CH(+)CH3 ---> C6H5CH(CH3)2   + H+

AlCl4- + H+ ---> HCl + AlCl3

From the given problem statement,he was attempting to prepare n−propylbenzene by alkylation benzene with 1−chloropropane and aluminum chloride,but 1-propyle benze was a major product in result.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.