BITSAT Chemistry Test - 4 - JEE MCQ

All the groups are o- and p-directive.
In (–OH) group, lone pair of electron present at oxygen (O -atom) , increases electron density for electrophile at o−  and p− positions. Thus, it is sharp o− and p− directive.)

This is nitration of benzene with nitronium electrophile.
As we know sulphuric acid has more acidity then nitric acid, so sulphuric acid gives proton and nitric acid takes proton to remove water and to form nitronium ion.

Chloroprene is obtained by treating vinylacetylene with HCI.

2-chloro-1,3-butadiene
(chloroprene)

Generally, alkenes can easily be oxidized by potassium permanganate and other oxidizing agents. The products formed depend on the reaction conditions. 
At low temperatures, with low concentrations of oxidizing reagents, alkenes form diols.
When more concentrated solutions of potassium permanganate and higher temperatures are employed (vigorous conditions), the reaction would not stop at this point.
The product of the reaction depends on the arrangement of groups around the carbon−carbon double bond. The potassium permanganate (VII) solution oxidizes the alkene by breaking the carbon - carbon double bond and replacing it with two carbon - oxgyen double bonds forming carbonyl compounds. 

• If there are two alkyl groups at one end of the bond, that part of the molecule will give a ketone.
• If there is one alkyl group and one hydrogen at one end of the bond, that part of the molecule will give a carboxylic acid.
• If there are two hydrogens at one end of the bond, that part of the molecule will give carbon dioxide and water.

In 2- methyl 2−pentene, one carbon contains two methyl groups on one side of the double bond and the other carbon has one alkyl chain and one hydrogen. Hence, the product will be one ketone and one carboxylic acid.

Methoxy group is electron releasing group it increases electron density of benzene nucleus - NO₂ group is electron withdrawing group, it decreases the electron density of benzene nucleus. Thus, the order of reaction with electrophilic regent is

The method of preparation of an alkane using soda lime (which is a mixture of  NaOH and CaO) is known as soda lime decarboxylation.
In soda lime decarboxylation, carboxylic acid is heated with soda lime, resulting into the formation of alkane having one carbon less than carboxylic acid.

Geometrical isomerism arises due to the restricted rotation in the molecule. In this molecule, a double bond causes restricted rotation and the geometrical isomers are formed. In the given compound, there are three double bonds and each carbon atom is substituted differently. So the number of geometrical isomers will be 2ⁿ = 2³ = 8, where n is the number of double bonds whose each carbon atom is differently substituted.

Since iodine is less electronegative than chlorine, therefore, ZnCl₂ react with ICl to form iodonium ion(I⁺) as electrophile which subsequently reacts with benzene to produce iodobenzene

First reagent is cold alkaline KMnO₄, which converts alkene into diol.
Second reagent is acidic K₂ Cr₂ O₇, which oxidises secondary alcohol into ketone. Tertiary alcohol is not oxidised.

The reaction Sequence is as Follows :

When a diazonium salt is treated with copper (I) chloride (Cu2Cl2) or copper (I) bromide (Cu2Br2), the corresponding haloarene is formed. This reaction is known as Sandmeyer reaction. It is used for introducing a chloro or bromo group in the benzene ring.

–CCl₃ group is m–directing due to -I and -H effect.

The reaction is Wurtz's type reaction and follows free radical mechanism.

Aliphatic SN¹ reaction is carried out in two steps. In first step carbocation is formed and its formation is based on the stability of carbonation. 
In the second step, the nucleophile is attracted to carbocation to give final products. Hence, an order of SN¹ is

The aryl halides e.g., chlorobenzene are less reactive as compared to alkyl halides towards nucleophilic reagents in either SN² or SN¹ reaction because carbon-halogen bond in the aryl halide is strong (due to its double bond character). 

It is Wurtz coupling reaction. In first step one chlorine is removed to generate nucleophile. After this intramolecular nucleophilic substitution takes place to form cyclic compound.
Hence, in given reaction cyclopropane is a final product.

Racemic tartaric acid is optically inactive due to external compensation.

Racemic tartaric acid is an equimolar mixture of optically active d- and l- forms. This form of tartaric acid is optically inactive due to external compensation.

In the presence of anhydrous ZnCl_2, phenol form salicyladehyde. It is Gattermann-aldehyde reaction.

It is an example of SN1SN1 reaction.
Rate of SN1 reaction α stability of carbocation SN1 reaction α stability of carbocation 
In option A carbocation formed after removing halogen is destabilized by −I-I effect.
In option B carbocation formed after removing halogen is stabilized by +M effect since lone pair is present at oxygen atom.
In option C carbocation formed after removing halogen is stabilized by +M effect of lone pair present on nitrogen atom but lone pair is also in conjugation with benzene ring therefore +M effect is less.
In option D carbocation formed after removing halogen is stabilized by +M effect of lone pair present on nitrogen atom and +M effect of nitrogen atom is more than that of oxygen atom. Hence, option D is most stable. 

Those substances which have same atomic number but different atomic weight are known as isotopes. The number of protons present in the nucleus of the atom is known as atomic number.

Therefore, on nitration it produce m-dinitrobenzene. 

the specific rate constant of a first order reaction depends on the temperature of the reaction. The rate constant, k , is a measure of the relationship between the rate of a chemical equation and the concentration of the reacting substance.

The law of conservation of mass can be best explained by Dalton’s law, because according to Dalton’s law atoms can neither be created nor destroyed.

The linkage present in protein molecules is known as peptide linkage.

We know that during expansions of an ideal gas in vacuum. The work done is zero as in vacuum there is no force of attraction or repulsion is taking place.

Chromyl chloride oxidise toluene as below

Schiff's reagent is a solution of rosaniline hydrochloride used for the detection of aldehyde group.

The pH of neutral solution is 7. The pH below 7 shows acidic and above 7 shows basic solution.

In an aq. solution hydrogen will not reduce Zn²⁺ as its reduction potential is lower than hydrogen.