(Saytzeff’s rule).

Give the equations of reactions for the preparation of phenol from cumene. Ease of hydrolysis of alkyl halides RI > R – Br > RCI > and t > s > p alkyl halides.

Classification of … P and Q are, respectively– asked Jun 3, 2019 in Chemistry by suman (71.4k points) kvpy; class-12; 0 votes.

It gives all the general reactions given by -OR group but 2° OR is less reactive as compared to 1° . Its IUPAC name is propane-l,2,3-triol.

1-propoxypropane can be synthesized from propan-1-ol by dehydration.

April 22, 2019. in CBSE. Ethylene glycol (CH2OH – CH2OH) is the first and most important member of dihydric alcohol series. When phenol is treated with chloroform (CHCl3) in the presence of sodium hydroxide, a −CHO group is introduced at the ortho position of the benzene ring. As a result, elimination dominates substitution. Reduction of aldehyde, ketones and esters with No Alcohol is called Bouveault-blanc reduction. 1. (i) Electrophilic substitution reactions The -OH group attached to the benzene ring activates it towards electrophilic substitution at ortho and para positions . 1. The introduction of acetyl (CH3CO-) group in phenols is known as acetylation. Because of the presence of polar -OH bond, phenols form intermolecular H-bonding with other phenol molecules and with water. As a result, the bond cleavage becomes easy. Boiling points of alkanes are higher than expected because of the presence of intermolecular hydrogen bonding in the polar molecules. This sodium phenoxide when treated with carbon dioxide, followed by acidification, undergoes electrophilic substitution to give ortho-hydroxybenzoic acid as the main product. 11.15.Explain why is ortho nitrophenol more acidic than ortho methoxyphenol?

It is prepared as follows. Give reason. Because of the presence of polar -OH bond, phenols form intermolecular H-bonding with other phenol molecules and with water.

6.trinitrophenol (picric acid) Higher Ka and lower pKa value corresponds to the stronger acid.

Better results are obtained in case of primary alkyl halides.

The intermediate is hydrolyzed in the presence of alkalis to produce salicyclaldehyde.

document.write(''); This is because o- nitrophenol is steam volatile due to intramolecular hydrogen bonding while p nitrophenol is less volatile due to intermolecular hydrogen bonding which causes the association of molecules. var now = new Date(); While separating a mixture of ortho and para nitrophenols by steam distillation, name the isomer which will be steam volatile. Extra energy is required to break these hydrogen bonds. These are generally called glycols because of their sweet taste. Write the equations for the preparation of phenol using these reagents. Explain the fact that in aryl alkyl ethers, (i) The alkoxy group activates the benzene ring towards electrophilic substitution and. It is soluble in water but insoluble in ether. var month = ("0" + (now.getMonth() + 1)).slice(-2);

Because of its tendency of formation of H-bonds, it is miscible with H2O and ethanol but not with ether. Also, the o-nitrophenoxide ion formed after the loss of protons is stabilized by resonance. function checkTime(i) { Ethers with two different alkyl groups are also cleaved in the same manner and results in the, formation of a primary halide (or smaller and less complex alkyl halide) by S R-O-R’ + HX → RX + R’OR, The order of reactivity of hydrogen halides is as follows HI > HBr > HCl, In ethers if one of the alkyl groups is a tertiary group, the halide formed is a tertiary halide by. It is a colourless, odourless, viscous and hygroscopic liquid.

Chemical Reactions of Alcohols 1.

These also exhibit chain isomerism and metamerism.

Similarly with carbon tetrachloride and alkali, c- and p-hydroxybenzoic acid are obtained. Give IUPAC names of the following ethers: 11.24. In this test, primary (1°) alcohols give red colour, secondary (2°) alcohols give blue colour and tertiary (3°) alcohols give no colouration. In case of secondary or tertiary alcohols, the alkyl group is hindered.

Preparation from alkene compound 2.

CLICK HERE  to watch them. CBSE Class 12 Chemistry Notes : Alcohols, Phenols and Ethers. 2. (i) 1-phenylethanol from a suitable alkene. Reading Time: 12min read 0.

To get fastest exam alerts and government job alerts in India, join our Telegram channel. Diethyl Ether is used as an anaesthesia in surgery . Hence, o-nitrophenol is steam volatile. After the formation of ethene, it is removed to shift the equilibrium in a forward direction.

Alcohols are weaker acids than water due to +1 group present in alcohols, which decreases the polarity of -O-H bond. (ii) Williamson’s synthesis Only primary alkyl halides when react with sodium alkoxide give ether while tertiary alkyl halides give alkene due to steric hindrance.

Similarly with carbon tetrachloride and alkali, c- and p-hydroxybenzoic acid are obtained.

An unsymmetrical ether is an ether where two groups on the two sides of an oxygen atom differ (i.e., have an unequal number of carbon atoms).

As a result, alcohols are comparatively more soluble in water than hydrocarbons of comparable molecular masses. This reaction is an electrophilic substitution reaction and electrophile is dichlorocarbene. It gives CH3OCH3 and CH3ONO.

var today = day + "-" + month + "-" + now.getFullYear(); 2. Ethers are the organic compounds in which two alkyl or aryl groups are attached to a divalent oxygen. glycerol gives HCOOH and HCHO.

d) Dehydration of alcohols It requires acid catalyst and the reaction proceeds via intermediate carbonium ion. (v) Dehydration of propan-2-ol to propene.

It is obtained as a by product in saponification reaction. (iii) When ethyl magnesium chloride is treated with methanal, an adduct is the produced which gives propan-1-ol on hydrolysis. Chemical Reactions of Alcohols and Phenols. glycerol gives HCOOH and HCHO. the aromatic ring towards electrophilic substitution reaction.