Question

Which of the following haloalkane is most reactive?
A. 1-chloropropane
B. 1-bromopropane
C. 2-chloropropane
D. 2-bromopropane

Answer 1

In the given question, 2-chloropropane and 2-bromopropane are secondary halides and 1-chloropropane and 1-bromopropane are primary halides. The order of reactivity depends on the nature of the halogen atom and the nature of the carbon atom to which halogen is bound.

Complete step by step answer:
Alkyl halides are the class of organic compounds where one or more halogen atoms are bound to an $sp^3$ hybridised orbital of an alkyl group. The halogen atoms are more electronegative than carbon atoms, and so the carbon -halogen bond is polarized.
The high reactivity of alkyl halides can be due to the polarisation of carbon -halogen bonds. Due to this, carbon develops a partial positive charge and halogens develop a partial negative charge.
The order of reactivity of halogens are,
I$odide > bromides > chlorides > fluorides$

The order of reactivity of alkanes are,
$Tertiary\; halide > secondary\; halide > primary\; halide$
Thus, bromopropane is the most reactive compound.

Hence the answer is option D .

Note: Hydrocarbons with at least one carbon-to-carbon double bond are termed as alkenes. They are also called olefins.
Based on the number of carbon atoms, the carbon atoms are bonded; they are classified as primary, secondary, tertiary, and quaternary carbon atoms. This can be found easily by just counting the number of carbon atoms to which it is attached. The carbons that are attached to only one other carbon is called a primary carbon. The carbons that are attached to two other carbon is called a secondary carbon.