Ncert Solutions Chemistry Class 12th

This is a short answer type question as classified in NCERT Exemplar

Alcohols such as ethanol  are made unfit for consumption by adding some additives like copper sulphate and pyridine which gives a foul smell, and  bad taste  to alcohol, it is known as denatured alcohol. 

This is a short answer type question as classified in NCERT Exemplar

The solubility of alcohol in water depends upon the following factors:

(a) Hydrogen bonding: Alcohols form hydrogen bonding with water due to the presence of -OH group in alcohol and hence alcohols are soluble in water. 

(b) Size  of alkyl or aryl group: The alkyl and aryl group are hydrophobic in nature and larger the size of  alkyl or aryl group of alcohol lesser will be the solubility of alcohol in water.

This is a short answer type question as classified in NCERT Exemplar

3-Methylpent-2-ene-1,2-diol

This is a short answer type question as classified in NCERT Exemplar

The IUPAC name of the given compound is:

(A) 3-Ethyl-5-methylhexane-2,4-diol

(B) 1-Methoxy-3-nitrocyclohexane

This is a short answer type question as classified in NCERT Exemplar

The  structure of glycerol is:

  CH₂—CH—CH₂

   |          |         |

  OH     OH  OH

The IUPAC of glycerol is Propane-1,2,3-triol.

This is a long answer type question as classified in NCERT Exemplar

(a) Cumene is the beginning element for the industrial production of phenol.

(b)

When bromine water is used to treat phenol. As a whitish precipitate, 2,4,6-tribromophenol is formed

(c) Benzene is normally halogenated in the presence of a Lewis acid, such as FeBr3, which polarises the halogen molecule. Even in the absence of Lewis acid, the polarisation of the bromine molecule occurs in the case of phenol. It's because the benzene ring's —OH group has a strong activating impact.

This is a long answer type question as classified in NCERT Exemplar

In case of anisole, methylphenyl oxonium ion, is formed by protonation of ether. The bond between O—CH₃ is weaker than the bond between O—C₆H₅ because the carbon of phenyl group is sp2 hybridised and there is partial double bond character. Therefore, the attack by I- ion breaks O—CH₃ bond to form CH₃I. Phenols do not react further to give halides because the sp2 hybridised carbon of phenol cannot undergo nucleophilic substitution reaction needed for conversion to the halide.

This is a Fill in the blanks Type Question as classified in NCERT Exemplar

Correct option:  C

A catalyst allows a chemical reaction to occur at a faster rate or under different conditions than it would otherwise. As a result, a catalyst affects the reaction's enthalpy change, or heat. As a result, in the presence of the reaction, the enthalpy does not vary, i.e., it remains constant, and no heat is produced or absorbed.