Test: Types of Organic Reactions - NEET MCQ

The reaction proceeds through the radical chain mechanism. The radical chain mechanism is characterized by three steps: initiation, propagation and termination.  Initiation requires an input of energy but after that the reaction is self-sustaining.  The first propagation step uses up one of the products from initiation, and the second propagation step makes another one, thus the cycle can continue until indefinitely.

Nitration and sulfonation of benzene are two examples of electrophilic aromatic substitution. The nitronium ion (NO²⁺) and sulfur trioxide (SO₃) are the electrophiles and individually react with benzene to give nitrobenzene and benzenesulfonic acid respectively.

A reagent that brings an electron pair is called a nucleophile.i,e., nucleus seeking and the reaction is then called nucleophilic reaction.During a reaction a nucleophilic attacks an electrophilic centre of the substrate which is that specific atom or part of the electrophile that is electron deficient.

When one molecule of alkynes react with mercuric sulphate and dilute sulphuric acid at 333 K it result into the formation of  carbonyl compounds.

Reaction involved:

Addition reactions are limited to chemical compounds that have multiple bonds, such as molecules with carbon–carbon double bonds (alkenes), or with triple bonds (alkynes). Two non-polar addition reactions exist as well, called free-radical addition and cycloadditions.

Propene, also known as propylene or methyl ethylene, is an unsaturated organic compound having the chemical formula . It has one double bond, and is the second simplest member of the alkene class of hydrocarbons.

For Cl and other halogen, we prioritise -I effect over +M effect because of their electron withdrawing nature. 
In firstcase, we have 3 -Cl which exerts maximum electron withdrawing nature, thus decreasing electron density on carboxylate which in turn, breaks O-H bond. With decrease in no. of Cl atoms, acidic strength decreases.
So, a is the strongest acid.

The three steps in the halogenation reaction are initiation, propagation and termination.

In the figure, BS means bond strength and EN means electronegativity. There one can see why HCl forms and not RCl.

The correct answer is option C
The reactivity of the halogens decreases in the following order: F_2​>Cl₂​>Br₂​>I₂​
fluorine is so explosively reactive it is difficult to control, and iodine is generally unreactive. Chlorination and bromination are normally exothermic.

A Friedel-Crafts alkylation reaction is an electrophilic aromatic substitution reaction in which a carbocation attacks an aromatic ring with the net result that one of the aromatic protons is replaced by an alkyl group. vinyl and aryl halides cannot be used to form carbocations.