Chapter 8, Problem 36P

Interpretation Introduction

Interpretation:

The relative rate of reaction, when $2-\text{methyl propene}$, propene and ethene react with HI, is to be explained.

Concept Introduction:

Electrophiles are electron deficient species which has positive or partially positive charge. Lewis acids are electrophiles which accept electron pair.

Nucleophiles are electron rich species which has negative or partially negative charge. Lewis bases are nucleophiles which donate electron pair.

Free radical is an atom, molecule or ion that has unpaired electrons which makes it highly chemically reactive.

Substitution reaction: A reaction in which one of the hydrogen atoms of a hydrocarbon or a functional group is substituted by any other functional group is called substitution reaction.

Elimination reaction: A reaction in which two substituent groups are detached and a double bond is formed is called elimination reaction.

Addition reaction: It is the reaction in which unsaturated bonds are converted to saturated molecules by the addition of molecules.

Carbocation is a molecule having a carbon atom bearing three bonds and a positive formal charge.

Carbocation are generally unstable because they do not have eight electrons to satisfy the octet rule.

The order of stability of carbocation is such that the tertiary carbocation is the most stable whereas the primary carbocation is the least stable, and secondary carbocation lies between primary and tertiary carbocations.

If primary carbocation is obtained in product, it rearranges itself to secondary or tertiary carbocation to form more stable product.

If secondary carbocation is obtained in product, it rearranges itself to tertiary carbocation to form more stable product.

The stability of carbocation: ${\text{3}}^{\text{o}}\text{carbocation}\text{>}{\text{2}}^{\text{o}}\text{carbocation}{\text{>1}}^{\text{o}}\text{carbocation}\text{>methyl}\text{carbocation}$

The addition reaction is the reaction in which unsaturated bonds are converted into saturated molecules by the addition of molecules.

The primary carbon atom is the one in which the required atom of carbon is attached to only one other atom of carbon. It is denoted by $1°$.

The secondary carbon atom is the one in which the required atom of carbon is attached to two other atoms of carbon. It is denoted by $2°$.

The tertiary carbon atom is the one in which the required atom of carbon is attached to three other atoms of carbon. It is denoted by $3°$.