Alcohols,Phenols And Ethers - Class 12 Engineering Chemistry - Extra Questions
How do you condemn the use of alcohol as a social practice.
Write a reasonable and detailed mechanism for the following transformation.
Write the IUPAC name.
b''
Write the name and formula of the second member of the carbon compounds having functional group-OH.
Write the mechanism for the preparation of ethanol form ethane.
Name the method which can give following product
Propan-1-ol cannot be prepared by acid catalysed hydration of propane, then how is propene converted into propan-1-ol?
Propene is converted to Prop-1-ol through Hydroboration Oxidation (Anti-Markonikoff's rule).
Write the stability of given alcohols
$$CH_3OH$$ , $$CH_3CH_2OH$$, $$CH_3CH_2CH_2OH$$
Identify missing products obtained in this reaction.
$$CH_{3}-CH_{2}-CH_{3}\xrightarrow{Br_{2}/hv}$$$$(A)\xrightarrow{aq KOH}(B)\xrightarrow[\Delta ]{H_{2SO_{4}}}(C)\xrightarrow[CCl_{4}]{Br_{2}}(D)$$
$$CH_3-\underset{\underset{\,\,\,\,CH_3}{|}}{C}H=CH_2\xrightarrow{Reagent}\,Alcohol$$Match the alcohol product with the suitable reagent.
The given IUPAC name is 1,1-dimethylcyclohexane-3-ol
Is the above statement correct?
All these attached to the benzene ring. The IUPAC name of the given compound is 4,4-dimethylcyclohexan-1-ol
Therefore, the statement is false.
The name of the compound is Cyclopent-1-en-3-ol
If true enter 1, else enter 0.
The name of the compound is isobutyl alcohol.
If true enter 1, else enter 0.
False.
There are 4 carbons in the longest chain. Two substitutes one methyl group and one alcohol both are attached at second carbon. Therefore, the given compound is tert-Amyl alcohol and its IUPAC name is 2-methyl-2-butanol.
Convert t-Butanol to the given compound.
Since the alkyl halides are reactive, they undergo double decomposition with Grignard reagent.
The given alcohol is _______ (primary/ secondary) alcohol.
(If your answer is primary type 1 else 2)
Suggest a sequence of reactions suitable for preparing propanol from $$2-propanol.$$
Show how would you synthesise the above alcohols from appropriate alkenes :
Addition of $$\displaystyle H_{2}O$$ to both these alkenes gives the desired alcohol.
How are the following conversions carried out?Propen $$\displaystyle \rightarrow $$ Propan-2-ol
Propan-2-ol can be prepared from propene by hydration as shown below:
How would you synthesize an alcohol from appropriate alkenes?
Writer the mechanism of acid dehydration of ethanol to yield ethene.
Step 1 involves the Protonation of Ethanol by acid
Step 2 is the rate determining step where carbocation is formed.
In Step 3, a proton is eliminated to form Ethene. Here, the acid consumed in the first step is released.
Step 2 is the rate determining step where carbocation is formed.
In Step 3, a proton is eliminated to form Ethene. Here, the acid consumed in the first step is released.
Write the equations involved in the following reaction.
Williamson ether synthesis.
Match the column I with column II.
How can you synthesize Ethanol from Ethene?
Explain why is ortho nitrophenol more acidic than ortho methoxyphenol?
Show how will you synthesise:
(i) 1-phenylethanol from a suitable alkene.
(ii) cyclohexylmethanol using an alkyl halide by an $$S_N2$$ reaction.
(iii) pentan-1-ol using a suitable alkyl halide.
$$(i)$$ $$1$$-phenylethanol can be prepared from ethylbenzene (styrene) by acid catalyzed hydration.
$$(ii)$$ Cyclohexylmethanol is prepared using chloromethylcyclohexane by a $$S_N2$$ reaction by treatment with $$NaOH$$. Hydroxide ion is the nucleophile.
$$(iii)$$ Pentan-$$1$$-ol can be prepared by using $$1$$-chloropentane by a $$S_N2$$ reaction by treatment with $$NaOH$$. Hydroxide ion is the nucleophile.
$$(ii)$$ Cyclohexylmethanol is prepared using chloromethylcyclohexane by a $$S_N2$$ reaction by treatment with $$NaOH$$. Hydroxide ion is the nucleophile.
$$(iii)$$ Pentan-$$1$$-ol can be prepared by using $$1$$-chloropentane by a $$S_N2$$ reaction by treatment with $$NaOH$$. Hydroxide ion is the nucleophile.
Write the mechanism of hydration of ethene to yield ethanol.
Three steps are involved in the mechanism of hydration of ethene to yield ethanol.
$$(1)$$ The electrophillic attack of hydronium ion protonates ethene to form carbocation.
$$(2)$$ Water (as a nucleophile) attacks carbocation.
$$(3)$$ Deprotonation gives ethanol.
The mechanism is shown above.
$$(1)$$ The electrophillic attack of hydronium ion protonates ethene to form carbocation.
$$(2)$$ Water (as a nucleophile) attacks carbocation.
$$(3)$$ Deprotonation gives ethanol.
The mechanism is shown above.
Write chemical reaction for the preparation of phenol from chlorobenzene.
Fusion of chlorobenzene with $$NaOH$$ (at $$623$$ K and $$320$$ atm pressure) produces sodium phenoxide. On acidification, it gives phenol.
How are the following conversions carried out?
(i) Propene $$\longrightarrow$$ Propan-2-ol
(ii) Benzyl chloride $$\longrightarrow$$ Benzyl alcohol
(iii) Ethyl magnesium chloride $$\longrightarrow$$ Propan-1-ol
(iv) Methyl magnesium bromide $$\longrightarrow$$ 2-Methylpropan-2-ol
Show how would you synthesise the following alcohols from appropriate alkenes?
Convertion of alkenes to alcohols can be carried out by the acid catalyzed hydration of alkenes.
A molecule of water is added across C=C double bond. Addition follows Markovnikov's rule.
A molecule of water is added across C=C double bond. Addition follows Markovnikov's rule.
Write the name and structure of an alcohol with four carbon atoms in its molecule.
Butanol is an alcohol which has four carbon atoms in its molecule. Its stuctural formula is $$CH_3CH_2CH_2CH_2OH$$.
How will you convert:(i) Propene to propan$$-1-$$ol? (ii) Ethanal to propan-2-ol?
(ii) Ethanal to propan-2-ol?
Write the IUPAC name of the given compound :
The IUPAC name of the given compound is 2-phenyl ethanol. The parent compound contains two $$C$$ atoms and an $$-OH$$ group. Hence, it is a derivative of ethanol. A phenyl group is present as a substituent on second carbon atom.
Draw the structure of major monohalo product in each of the following reactions.
R.E.F image
Addition in presence of peroxide yields product according to anti - Markovnikov rule of addition.
Write the equations involved in the following reactions:
(i) Reimer - Tietmann reaction
(ii) Williamson synthesis
The equations involved in the following reactions are as shown
(i) Reimer - Tietmann reaction: Sodium phenoxide on treatment with chloroform in presence of aq KOH gives Salicylaldehyde.
(ii) Williamson synthesis: Sodium phenoxide reacts with methyl iodide to form an ether.
(i) Reimer - Tietmann reaction: Sodium phenoxide on treatment with chloroform in presence of aq KOH gives Salicylaldehyde.
(ii) Williamson synthesis: Sodium phenoxide reacts with methyl iodide to form an ether.
Arrange the following compounds in the decreasing order of their boiling points.
a) Pentan-1-ol
b) 2-Methylbutan-2-ol
c) 3-Methylbutan-2-ol
Why do alcohols have higher boiling points than haloalkanes of the same molecular mass?
Arrange the following in the decreasing order of their boiling points:
$$\displaystyle CH_3CH_2OH, HOCH_2CH_2OH, CH_3CH_2Cl$$.
Can we dry ethanol by anhydrous $$CaCl_2$$?
Liquid alkalies as well as alcohols are added to water. What observation do you predict? Justify your prediction.
Since alcohol and phenol are acidic in nature. So when their solution are added in the water along with the alkali solution, they form corresponding salts in the solution.
Ethyl alcohol and propane have nearly equal molecular weights. But, the former is a liquid with high boiling point and the latter is a gas with low boiling point. Give reason.
What is the major product when ethanol is treated with $$conc. H_{2}SO_{4}$$ at $$413\ K$$?
(a) Write the IUPAC name and structural formula of secondary-Butyl alcohol.
(b) Give equations for preparation of phenol from the following compounds:
(i) Benzene
(ii) Aniline.
(c) Write the resonance structures of phenol.
(a) The IUPAC name of secondary-Butyl alcohol is butan-2-ol.
(b) Preparation of phenol:
(i) From benzene (Raschig process):
Benzene reacts with HCl and O$$_2$$ in presence of CuCl$$_2$$/ FeCl$$_3$$ catalyst to form chlorobenzene. On treatement with steam at 425 deg C, chlorobenzene gives phenol.
(ii) From aniline:
Diazotisation of aniline with nitrous acid gives benzene diazonium chloride. Benzene diazonium chloride when treated with water in presence of dil sulphuric acid gives phenol.
(c) The resonance structures of phenol are as shown.
(b) Preparation of phenol:
(i) From benzene (Raschig process):
Benzene reacts with HCl and O$$_2$$ in presence of CuCl$$_2$$/ FeCl$$_3$$ catalyst to form chlorobenzene. On treatement with steam at 425 deg C, chlorobenzene gives phenol.
(ii) From aniline:
Diazotisation of aniline with nitrous acid gives benzene diazonium chloride. Benzene diazonium chloride when treated with water in presence of dil sulphuric acid gives phenol.
(c) The resonance structures of phenol are as shown.
How is carbolic acid prepared from the following compound?
(i) Aniline
(ii) Chlorobenzene and steam at $$698$$K?
Draw structure of DDT. Write its environmental effects.
Mention two physical properties of carbolic acid.
Some of the environmental effects of DDT are.
(i) It is not readily metabolised by animals.(ii) It is deposited and stored in fatty tissues..
The two physical properties of carbolic acid or phenol are:
(i) Pure phenol is a colourless, hygroscopic, crystalline solid with typical phenolic odour. On exposure to air and light, it turns pink due to partial oxidation.
(ii) Phenol has low melting point $$(316K)$$, but has higher boiling point $$(455K)$$ due to intermolecular hydrogen bonding.
Write balanced chemical equations for the action of:
(1) Phosphorus trichloride on propan-2-ol
(2) Hydrogen bromide on styrene in the presence of a peroxide.
(3) Methyl bromide on silver propanoate.
(1) Phosphorus trichloride on propan-2-ol
(2) Hydrogen bromide on styrene in the presence of a peroxide.
(3) Methyl bromide on silver propanoate.
(1) When propan -2-ol is treated with $$PCl_3$$, 2-chloropropane is obtained.
$$\underset{Propan-2-ol}{3CH_3-\underset{OH}{\underset{|}{C}H}} - CH_3+\underset{Phosphorus\\trichloride}{PCl_3} \xrightarrow{\Delta} \underset{2-Chloropropane}{3CH_3 - \underset{Cl}{\underset{|}{C}}H - CH_3} + H_3PO_3$$
(2) When styrene is treated with HBr in the presence of peroxide, 1-Bromo-2-phenyl ethane is obtained.
(Ref. image)
(3) When methyl bromide is treated with sliver propanoate, methyl propanoate and silver bromide precipitate is obtained.
$$\underset{sliver\, propanotae}{H_3C - CH_2 - \overset{O}{\overset{||}{C}} - Ag }+ \underset{Methyl \, Bromide}{CH_3 Br }\xrightarrow{\Delta} \underset{Methyl\, propanoate}{CH_3 - CH_3 - \overset{O}{\overset{||}{C}} - O - CH_3} + Ag \,Br (\downarrow)$$
Write the chemical reactions of $$C_{2}H_{5}OH$$ with $$PCl_{3}$$ and $$PCl_{5}$$ separately
What is Williamson's Synthesis? Give equation.
Ethanol is heated with excess concentrated $$H_2SO_4$$ at 443K.
i) Name the reaction that occurs and explain it.
ii) Write the equation for the above reaction.
iii) What is the product formed? What happens when this gas is passed through bromine water?
iv) When ethanol vapour is passed through bromine water, why does no change occur?
Match the following compounds with their functional groups:
| S.No | Compounds | Functional Groups |
| 1. | Alcohol | $$>C=O$$ |
| 2. | Aldehyde | $$-OH$$ |
| 3. | Ketone | $$-COOH$$ |
| 4. | Carboxylic acid | $$-CHO$$ |
Write a balanced equation using the correct symbols for these chemical reactions:
i) Action of hydrogen on ethene in the presence of nickel catalyst.
ii) Combustion of methane evolving carbondioxide and water.
iii) Dehydrogenation of ethanol.
iv) Decarboxylation of Sodium salt of ethanoic acid.
The organic compound A of molecular formula $$C_2H_4O_2$$ gives brisk effervescence with sodium bicarbonate solution. The sodium salt of A on treatment with soda lime gives a hydrocarbon B of molecular massIt belongs to the first member of the alkane family. What are A and B and how will you prepare A from ethanol?
How is diethyl ether prepared by continuous etherification process?
If the starting material is labeled with deuterium as indicated, how many total deuterium atoms will be present in the major elimination product of the above reactions?
A student prepared methanol in the laboratory by the addition of $$266\ g$$ of $$CO$$ and $$60\ g$$ of $$H_{2}$$, as shown below.
$$CO(g) + H_{2}(g) \rightarrow CH_{3}OH(l)$$
(a) Find out the limiting reagent.
(b) Calculate the amount of methanol produced and the amount of excess reactant remaining after the completion of the reaction.
Write the IUPAC name of the following.
$$CH_3-\!\!\!\!\!\!\overset{\,\,\,\,CH_3}{\overset{|}{\underset{\,\,\,\,\,C_2H_5}{\underset{|}{C}}}\!\!\!\!-}\,\underset{OH}{\underset{|}{C}H}-CH_3$$
The IUPAC name is 3,3-dimethylpentan-2-ol.
The longest continuous chain of C atoms has 5 C atoms.
Hence, the parent chain is pentane. An -OH group is present as a substituent on second C atom and is named as suffix -2-ol where 2 indicates the position of C atom to which -OH group is attached.
Two methyl groups are present as substituents on third C atom are named as prefix 3,3-dimethyl where 3 indicates the position of C atom to which methyl groups are attached.
The prefix 'di' indicates 2. The numbering is done from the end which gives the lowest possible locants.
How will you prepare isopropyl alcohol from propene?
IUPAC name of t-butyl alcohol ?
t-butyl alcohol is referred to the image above:
$$IUPAC: 2-Methylpropane-2-ol.$$
Find the reagents used for conversion.
R.E.F image
(Anti-markonikov addition)
Carry out the following conversions:
(i) Phenol to benzoquinone.
(ii) Propanone to 2-Methylpropan-2-ol.
(iii) Propene to propan-2-ol.
How are the following conversions carried out ?
(i) Propene to propane-2-ol
(ii) Benzyl chloride to Benzyl alcohol
(iii) Anisole to p-Bromoanisole
Identify the products 'A' 'B' and 'C' in the following reaction
$$CH_3 - CH_2 - OH \overset{Cu}{\underset{573 K}{\longrightarrow}}$$ A $$\overset{NaCN+ dil.HCl}{\longrightarrow}$$ B $$\underset{dil.HCl}{\longrightarrow} C$$?
Maximum enol content is in ?
Give the IUPAC name of $${CH}_{3}-{CH}_{2}-CH(OH)-{CH}_{3}$$.
Write the three steps involved in the mechanism of acid catalysed dehydration of ethanol to ethene.
The three steps involved in the mechanism of acid catalysed dehydration of ethanol to ethene are as shown.
Give the IUPAC name of the following compound.
Give the IUPAC name of the following compound.
Mark the correct order of decreasing acid strength of the following compounds.
As positive charge on the ring increases, acidic strength increases.
$$m$$ is the mesomeric effect
$$I$$ is the inductive effect.
$$+m /+I$$ increases the electron density.
$$-m /-I$$ decreases the electron density.
Write the IUPAC name of the given compound.
$$1.$$ Organic compounds containing substituents from Group $$C$$ are named following this sequence of steps, as indicated on the examples below:
Step $$1$$: Find the longest continuous carbon chain. Determine the root name for this parent chain. In cyclic compounds, the ring is usually considered the parent chain, unless it is attached to a long chain of carbons; indicate a ring with the prefix "cyclo" before the root name.
Step $$2$$: Number the chain in the direction such that the position number of the first substituent is the smaller number. If the first substituents from either end have the same number, the number so that the second substituent has the smaller number, etc.
Step $$3$$: Determine the name and position number of each substituent.
Step $$4$$: Indicate the number of identical groups by the prefixes di, tri, tetra, etc.
Step $$5$$: Place the position numbers and names of the substituents groups, in alphabetical order, before the root name. In alphabetizing ignore prefixes like sec-, tert-, di, tri, etc., but include iso and cyclo. Always include a position number for each substituent, regardless of redundancies.
So, the IUPAC name of the compound shown above is $$2-Methyl$$ $$-2-cyclohexen-1-ol$$
Predict the major product of acid catalysed dehydration:
(i) 1-methyl cyclohexanol
(ii) Butan-1-ol
Due to Saytzeff rule, in $$(i)$$ the product where double bond is formed at the more substituted carbon is the major product. But as Saytzeff rule is only valid for 2° and 3° alcohols, a primary alcohol like $$(ii)$$ will form a terminal alkene as the major product.
Write the general formula of ether.
The general formula of ether is $$C_4H_{10}O$$
$$H_2C=CH-CH_2OH$$Classify the following as primary, secondary and tertiary alcohol.
Complete this reaction.
Convert 1-iodopropane to propan -1-ol.
1-iodopropane is converted into propan-1-ol by hydrolysis of 1-iodopropane in presence of aqueous NaOH.
Convert Ethanal to Isopropyl alcohol.
Give the IUPAC name for the following alcohols. Classify as primary or secondary or teritiary alcohol.
In the given compound, the $$-OH$$ group is attached to the tertiary carbon atom. Thus, the given compound is a tertiary alcohol.
Also, for IUPAC name the compound contain phenyl group attached to the carbon number 4.
The $$-OH$$ group and methyl groups are attached to the carbon number 2.
Also, there is a double bond between carbon number 3 and 4.
Thus, The IUPAC name for this alcohol is $$2-methyl-4-phenylbut-3-en-2-ol$$
Give the IUPAC name for the following alcohols. Classify as primary or secondary or teritiary alcohol. $$(C_2H_5)_3C-OH$$
Give the IUPAC name for the following alcohols. Classify as primary or secondary or teritiary alcohol. $$(CH_3)_3C-\underset{\underset{\,\,\,OH}{|}}CH-C_2H_5$$
In the given compound, the $$-OH$$ group is attached to the secondary carbon atom. Thus, the given compound is a secondary alcohol.
Also, in the given compound the parent chain contains 5 carbon atom and the $$-OH$$ group is attached to the third carbon atom and a methyl group is attached to the 2 carbon atom.
The IUPAC name for this alcohol is $$2,2-Dimethyl-3-pentanol$$
Give the IUPAC name for the following alcohols. Classify as primary or secondary or teritiary alcohol.
In the given compound, the hydroxy $$-OH$$ group is attached to the secondary carbon atom. Thus, the given alcohol is a secondary alcohol.
Also, in this compound, the phenyl group is attached to the third carbon atom and the $$-OH$$ group is attached to the carbon number 2.
Thus, The IUPAC name for this alcohol is $$3-phenyl-2-butanol$$
Write the mechanism of hydration of ethylene to ethyl alcohol.
The mechanism of hydration of ethylene to ethyl alcohol is shown above.
Give the IUPAC name for the following alcohols. Classify as primary or secondary or teritiary alcohol. $$CH_2=CH-CH_2-CH_2-OH$$
Give the IUPAC name for the following alcohols. Classify as primary or secondary or teritiary alcohol.
In the given compound, the $$-OH$$ group is attached to the tertiary carbon atom. Thus, the given compound is a tertiary alcohol.
Also, for IUPAC the parent chain 4 carbon atoms and the $$-OH$$ group and phenyl group are attached to the carbon number 2.
So, the IUPAC name of this alcohol is $$2-phenyl-2-butanol$$ and this is a tertiary alcohol.
Give the IUPAC name for the following alcohols. Classify as primary or secondary or teritiary alcohol. $$CH_3 - \underset{\,\,\,OH}{\underset{|}{CH}} - \overset{\,\,\,\,\,\,\,\,CH_3}{\overset{|}{CH}} - CH_3$$
Since $$-OH$$ is give more preference while naming so numbering will start from L.H.S.
$$3$$-methyl-$$2$$-butan-$$2$$-ol, it is alcohol since $$C$$ of $$OH$$ attached to $$2$$ carbons.
Write the iUPAC name of the following compound.
This is alcohol. Numbering should be started from that carbon containing $$-OH$$ group. The IUPAC name is $$1-cyclohexanol$$ .
$$CH_2OHCH_2OH$$Write IUPAC name of the above compound.
Write the IUPAC names of phenols given.
Can you explain why is bimolecular dehydran not appropriate for the preparation of ethyl methyl ether?
The IUPAC name of the compound is:$$H_2=CH-\underset{\underset{\,\,\,CH_3}{|}}CH-\underset{\underset{\,\,\,\,\,C_2H_5}{|}}CH-\underset{\underset{\,\,OH}{|}}CH-CH_3$$
Arrange the following in increasing order of boiling points
Write the product $$(CH_{3})_{3}C-OH\xrightarrow[573 K]{Cu}$$
Tertiary alcohol when react with copper at 573K dehydration takes place and alkene is formed while primary and secondary alcohol on reaction gives aldehyde and ketone by dehydrogenation.
Write the IUPAC name of the given compound.$$H-\overset { H }{ \overset { | }{ \underset { H }{ \underset { | }{ C } } } } -\overset { H }{ \overset { | }{ \underset {O H }{ \underset { | }{ C } } } } -\overset { H }{ \overset { | }{ \underset { H }{ \underset { | }{ C } } } } -\overset { H }{ \overset { | }{ \underset { CH_3 }{ \underset { | }{ C } } } } -\overset { H }{ \overset { | }{ \underset { H }{ \underset { | }{ C } } } } -H$$
Arrange according boiling point: $$CH_3 \, CH_2 CH_3 , \, CH_3 CHO , \, CH_3 CH_2 OH, \, CH_3 OCH_3$$.
Identify X and Y.
$$\quad \quad \quad \quad OH\\ \quad \quad \quad \quad |\\ { CH }_{ 3 }-{ CH-CH }_{ 2 }{ CH }_{ 3 }\xrightarrow { 607.{ H }_{ 2 }SO_{ 4 },373k } \quad X+Y$$
We will obtain But-1-ene and But-2-ene as $$X$$ and $$Y$$.
What will be the product of the compound?
$$Ts-Cl$$ is a tosyl-chloride.it is an activating group of alcohol.
Write structures of the compound of following IUPAC name :
$$2-Methylbutan-2-ol$$
$$CH_3COOCH_2CH_3+CH_3MgI\rightarrow ?$$
How will you convect ethanol into ethylmethyl ketone?
How is phenol (carbolic acid) prepared from Rasching's process?
In this process, first benzene is converted into chlorobenzene. Chlorobenzene is then converted into phenol by hydration.
What is the action of following reagent on phenol?
Bromine in $${ CS }_{ 2 }$$ at low temperature :
Bromine in $${ CS }_{ 2 }$$ at low temperature :
Give reasons :
o-nitrophenol is more volatile than p-nitrophenol
How the following conversion can be carried out?
Ethanol to propanenitrile
Toluene to benzyl alcohol
What are ethers?
Explain: Methanol is more soluble in water than Propan-1-ol.
Write the mechanism of the following reaction:
2CH$$_{3}$$CH$$_{2}$$OH $$\underrightarrow {{ H}^{ + } }$$ CH$$_{3}$$CH$$_{2}$$OCH$$_{2}$$CH$$_{3}$$
Give reasons:
p-nitro phenol is more acidic than p-methyl phenol.
Write the name of reactant used for the preparation ethyl t-butyl ether
Write the structure of the compound whose IUPAC name is :
3 - Cyclohexylpentan - 3 - ol
Write IUPAC names of
Hint: Numbering is given in such a way that functional group and substituent gets the least number.
Explanation:
- The numbering is given from the Carbon close to $$2$$ methyl groups. It is shown as follows:
- The parent chain consist of $$5$$ carbon atoms, alcohol group present on $$3^{rd}$$ carbon atom, $$2$$ methyl groups on $$2^{nd}$$ carbon atom and $$1$$ methyl group at $$4^{th}$$carbon atom.
- Thus, the IUPAC name will be $$2,2,4-trimethylpentan-3-ol$$.
How are the following conversions carried out? (xviii) Benzene to diphenyl
How to convert methanol into ethanol? Write chemical equations only.
Write down the dehydration products of the given alcohols.
Dehydration means removal of water from the compound. The dehydration products of the given alcohols are respectively given above.
Dehydration of alcohol to form alkene is an ........ reaction.
What happens when :
Ethyl alcohol is heated at $$170^{\circ}C$$ with excess of $$conc. H_{2}SO_{4}$$?
When ethanol is heated with an excess of concentrated sulphuric acid at a temperature of 170°C, it produces ethene as final product. The concentrated acid acts only as a dehydrating agent and it is recovered unchanged.
Complete the following equations :
$$CH_{3}CH_{2} CH = CH_{2}\xrightarrow {CHCl_{3}} (A)\xrightarrow {NaOH} (B) $$.
$$CH_{3}CH_{2} CH = CH_{2}\xrightarrow {CHCl_{3}} (A)\xrightarrow {NaOH} (B) $$.
Give the IUPAC names of the following compounds:
Isopropyl alcohol
The ease of dehydration of alcohols is in the order _________ $$>$$ secondary $$>$$ __________.
Boiling points of alcohols are ________ than those of corresponding alkanes.
Complete the above equation.
How will you obtain ethylene from ethyl alcohol?
Ethanol can be dehydrated to give ethene by heating it with an excess of concentrated sulphuric acid at about 180°C.
Write IUPAC name of the following.
Write the structural formula and IUPAC names of the alcoholic isomers with molecular formula $$C_4H_{10}O$$.
How will you obtain iodoform from ethyl alcohol?
When ethanol is warmed $$(60^oC)$$ with iodine in the presence of an alkali $$(NaOH \ or\ Na_2CO_3)$$, iodoform is obtained
Write IUPAC name of the following.
Isoamyl alcohol.
Isoamyl alcohol.
Write IUPAC name of the following.
Chloral hydrate.
Chloral hydrate.
Write IUPAC name of the following.
What happens when vapour of ethyl alcohol is passed through heated aluminium oxide at $$360^o$$C?
Write the equation for preparing ethyl alcohol in one step only from Ethylene.
The following name is inconsistent with the prevalent rules. Rename the compound in accordance with the accepted conventions:
$$2-Phenyl-3-butanol$$.
Explain the mechanism of the following reactions:
(a) Bromine on ethylene.
(b) $$HBr$$ on ethylene.
How will you obtain the following from propene?
$$n-Propyl\ alcohol$$.
$$n-Propyl\ alcohol$$.
Give the mechanism of :
Outline a synthesis of alcohol from the indicated staring material.
Allyl alcohol from propene.
Outline a synthesis of alcohol from the indicated starting material.
Isopropyl alcohol from a hydrocarbon.
Write down the name and structure of the compound obtained by dehydration of ethyl alcohol.
Ethanol can be dehydrated to give ethene by heating it with an excess of concentrated sulphuric acid at about 170°C.
Complete the following equations:
$$2C_{6}H_{5}Cl + Na \xrightarrow {Ether}$$.
-
Fill in the blanks:
Amongst the three isomers of nitrophenol, the one that is least soluble in water is ________.
How will you prepare the following compounds from benzene?
Resorcinol.
Resorcinol is produced in several steps from benzene, starting with dialkylation with propylene to give 1,3-diisopropylbenzene. Oxidation and Hock rearrangement of this disubstituted arene gives acetone and resorcinol.
With specific compounds write equations for the reactions involved in the following conversions:
An aromatic hydrocarbon to its hydroxy derivative.
How will you prepare the following compounds from benzene?
$$m-Nitrophenol$$.
m-Nitrophenol can be prepared by diazotizing m-nitroaniline and subsequently heating with a large volume of water.
$$m-nitro\ ethyl \ benzene$$ on $$Br_2$$ and uv light,, What is the product ?
$$\text{In the presence of light, side chain (free radical) halogenation occurs at the benzylic hydrogen.}$$
Give the major product of hydration of the above alkene.
Give the major product of hydration of the following alkene.
$$C_3H_6(CH_3-CH=CH_2)\overset{H^+}{\underset{D_2O}{\rightarrow}}?$$
Identify the functional group present in the following compound and name it according to IUPAC system: $$CH_{3}OH$$.
Give the major product of hydration of the following alkene.
$$C_3H_6(CH_3-CH=CH_2)\overset{D^+}{\underset{D_2O}{\rightarrow}}?$$
Write the molecular formula of ethanol.
Give the major product of hydration of the following alkene.
$$C_3H_6(CH_3-CH=CH_2)\overset{D^+}{\underset{HOH}{\rightarrow}}?$$
Identify (F)
Write IUPAC name of the following compounds:
$$CH_3 - \underset{OH}{\underset{|}{CH}} - \underset{OH}{\underset{|}{CH}} - CH_3$$
Write IUPAC name of the following compounds:
$$HO - CH_2 - \underset{OH}{\underset{|}{CH}} - CH_2 - OH$$
Write IUPAC name of the following compounds:
Identify A and B in the following reactions:
How are the following conversions carried out?
Propanol to 1-propoxypropane
Write the IUPAC name of the following compound:
Write the IUPAC name of the following compound:
How are the following conversions carried out?
Propanol to propan-2-ol
Give Reasons:
Relative ease of dehydration of alcohols is $$3^\circ>2^\circ>1^\circ$$.
What is the effect of drinking methanol?
Write the main product(s) in each of the following reaction:
How do you obtain the following?
Propan-2-ol from propene
Give the trivial (common) names and the $$IUPAC$$ names of the following:
$$CH_{3}OH$$
Give the trivial (common) names and the $$IUPAC$$ names of the following:
$$C_{2}H_{5}OH$$
What are alcohols? State their sources
State the method of preparation of ethanol: by hydrolysis of ethene
Complete the reaction equation:
Name an organic compound which is: Called 'wood spirit
How do you convert the following:
i) Phenol to Anisole
ii) Ethanol to Propan-2-ol
i) Refer Image
ii) $$CH_3CH_2OH\xrightarrow{PCC}CH_3CHO\xrightarrow{CH_3MgI}CH_3-CH(OMgI)CH_3\xrightarrow{H_2O}CH_3-CH(OH)-CH_3$$
Ethanol Propan-2-ol
ii) $$CH_3CH_2OH\xrightarrow{PCC}CH_3CHO\xrightarrow{CH_3MgI}CH_3-CH(OMgI)CH_3\xrightarrow{H_2O}CH_3-CH(OH)-CH_3$$
Ethanol Propan-2-ol
What is the molecular formula of the alcohol which can be derived from propane?
Name an organic compound which is: Made from water gas
Write structure of the compound whose IUPAC name is as follows:
$$3$$-Chloromethylpentan-l-ol
Draw the structures of all isomeric alcohols of molecular formula $$C_5H_{12}O$$ and give their IUPAC names.
Identify if pentanol is insoluble, partially soluble or highly soluble in water?
Write the general formula of alcohol.
Name the reagent used in the following reaction:
Dehydration of propan-2-ol to propene.
Show how would you synthesise the above alcohol from appropriate alkene?
Acid hydration of Pent-$$2$$-ene produces Penton-$$3$$-ol along with penton-$$2$$-ol. Hence first rxn using Pent-1-ene is preferred.
Write the equation of the reaction of hydrogen iodide with:
$$1$$-propoxypropane
$$1$$-propoxypropane
Write the structural formulae for the following IUPAC
propan-2ol
What happens when
chlorobenzene is subjected to hydrolysis
Write IUPAC name of the above compound:
Explain the following with one example:
Dehydration
Dehydration
“Dehydration reactions can be defined as the chemical reactions in which a water molecule is eliminated from the reactant molecule. The process of combination of two molecules with the elimination of water molecule is called dehydration synthesis.”
This is because the term dehydration is used for ‘losing water’ and synthesis represents the formation of the new substance, therefore, dehydration synthesis is the elimination of water with the formation of new compounds. Definitely combination of two molecules will form a large compound and water molecule will eliminate and form as a by-product during the reaction.
Write down the IUPAC name of the given compound.
Write the IUPAC name of the following organic compound:
$$CH_3 - CH_2 - CH_2 - CH_2 - CH_2 - OH$$
Write the IUPAC name of ethyl alcohol.
Write down the IUPAC name of the compound given below:
$$CH_3 - CH_2 - CH_2 - OH$$
Write down the IUPAC name of the compounds given above and and then write the name of the isomerism exhibited by it.
Can you write the $$IUPAC$$ names of these two compounds?
$$CH_2-OH, CH_3 -CH_2-OH$$
State how the following conversions can be carried out.
Ethene to Ethyl alcohol.
An optically active alcohol A $$\displaystyle \left ( C_{6}H_{10}O \right )$$ absorbs 2 mol of hydrogen per mole of A upon catalytic hydrogenation and gives a product B. The compound B is resistant to oxidation by $$\displaystyle CrO_{3}$$ and does not show any optical activity. Deduce the structures of A and B.
Compound A is unsaturated monohydric alcohol and it has either two C=C bonds or one triple bond. Compound A is optically active and after hydrogenation optically inactive compound B is obtained which is not oxidised with $$CrO_3$$. Hence, in it $$-OH$$ group is attached with tertiary C-atom i.e. it is a tertiary alcohol.
Conversion of given reaction to the given product will take place in how many step?
3,3-dimethyloctan-4-ol is converted to 3,3-dimethyloctan-4-one by PCC oxidation. PCC oxidises secondary hydroxyl group to keto group. Clemmensen reduction with $$Zn/ Hg$$ and conc. $$HCl$$ converts carbonyl group to methylene group. It converts 3,3-dimethyloctan-4-one to 3,3-dimethyloctane.
Match the compounds in Column I with their characteristics/tests/reactions (s) reagent(s)/stereochemistry/isomer(s) given in Column II. Matching can be one or more than one.
| Column I | Column II |
| Reaction | Product and name of the reaction |
Write the structrual formula of the major product in the following case:
Ethene mixed with air is passed under pressure over a silver catalyst at $$250^{\circ} C$$.
Hence, when ethene mixed with air is passed under pressure over a silver catalyst at $$250^oC$$, we get oxirane as the major product.
Identify total number of 1, 2 shift during following dehydration reaction ?
Only one 1, 2 shift occurs during the dehydration reaction.
The shift of hydride ion from first carbon to second carbon is called as 1,2-hydride shift. The hydride shift occurs to get the more stable carbocation.
Explain the following with an example.
(i) Kolbes reaction.
(ii) Reimer-Tiemann reaction.
(iii) Williamson ether synthesis.
(iv) Unsymmetrical ether.
(i) Draw the structures of all isomeric alcohols of molecular formula $$C_5H_{12}O$$ and give their IUPAC names.
(ii) Classify the isomers of alcohols in above question as primary, secondaryand tertiary alcohols.
The structures of all isomeric alcohols of molecular formula $$C_5H_{12}O$$ alongwith their IUPAC names are as shown.
Their classification primary, secondary and tertiary alcohols is shown in parenthesis.
Their classification primary, secondary and tertiary alcohols is shown in parenthesis.
What is meant by hydroboration-oxidation reaction? Illustrate it with an example.
Hydroboration-oxidation reaction is the addition of borane followed by oxidation.
For example, propene on hydroboration-oxidation gives propan-$$1$$-ol.
The reaction of propene with diborane gives trialkyl borane as an addition product.
Oxidation by hydrogen peroxide in presence of aqueous sodium hydroxide gives propan-$$1$$-ol.
For example, propene on hydroboration-oxidation gives propan-$$1$$-ol.
The reaction of propene with diborane gives trialkyl borane as an addition product.
Oxidation by hydrogen peroxide in presence of aqueous sodium hydroxide gives propan-$$1$$-ol.
When 3-methylbutan-2-ol is treated with HBr, the following reaction takes place:
Give a mechanism for this reaction.
(Hint : The secondary carbocation formed in step II rearranges to a more stable tertiary carbocation by a hydride ion shift from 3rd carbon atom.)
The mechanism for the reaction between $$3$$-methylbutan-$$2$$-ol and HBr is shown above.
In the first step, $$-OH$$ group is protonated. In the second step, a molecule of water is lost to form secondary carbocation.
Third step is the rearrangement of less stable secondary carbocation to more stable tertiary carbocation through $$1,2$$-hydride shift.
Final step is the nucelophilic attack of bromide ion on tertiary carbocation to form $$2$$-bromo-$$2$$-methylbutane.
In the first step, $$-OH$$ group is protonated. In the second step, a molecule of water is lost to form secondary carbocation.
Third step is the rearrangement of less stable secondary carbocation to more stable tertiary carbocation through $$1,2$$-hydride shift.
Final step is the nucelophilic attack of bromide ion on tertiary carbocation to form $$2$$-bromo-$$2$$-methylbutane.
Write IUPAC name of the given compound:
As here $$R-OH$$ is functional group so parent chain contain carbon having $$-OH$$ that carbon should get lowest numbering. Hence the numbering should start from right-hand side as from right side substituents get lowest numbering.
Explain the mechanism of esterification. Write the reactions involved in dehydration of $${1}^{o}$$, $${2}^{o}$$ and $${3}^{o}$$ alcohols.
The mechanism of esterification:
The carbonyl oxygen of the carboxylic acid is protonated. This increases the positive character of carbonyl carbon. The nucleophile (alcohol) attacks the carbonyl carbon. This is followed by intramolecular proton transfer and loss of water molecule. In the final step, deprotonation gives ester.
Dehydration of primary alcohol:
$$\displaystyle CH_3-CH_2-OH \xrightarrow [443K]{95 \text {%} H_2SO_4} CH_2=CH_2+H_2O$$
Dehydration of secondary alcohol:
$$\displaystyle CH_3-CH(OH)-CH_3 \xrightarrow [373K]{60\text {%} H_2SO_4} CH_3-CH=CH_2+H_2O$$
Dehydration of tertiary alcohol:
$$\displaystyle CH_3-CH(OH)(CH_3)-CH_3 \xrightarrow [423K]{Al_2O_3} CH_3-C(CH_3)=CH_2 +H_2O$$
The carbonyl oxygen of the carboxylic acid is protonated. This increases the positive character of carbonyl carbon. The nucleophile (alcohol) attacks the carbonyl carbon. This is followed by intramolecular proton transfer and loss of water molecule. In the final step, deprotonation gives ester.
Dehydration of primary alcohol:
$$\displaystyle CH_3-CH_2-OH \xrightarrow [443K]{95 \text {%} H_2SO_4} CH_2=CH_2+H_2O$$
Dehydration of secondary alcohol:
$$\displaystyle CH_3-CH(OH)-CH_3 \xrightarrow [373K]{60\text {%} H_2SO_4} CH_3-CH=CH_2+H_2O$$
Dehydration of tertiary alcohol:
$$\displaystyle CH_3-CH(OH)(CH_3)-CH_3 \xrightarrow [423K]{Al_2O_3} CH_3-C(CH_3)=CH_2 +H_2O$$
Write the correct pair of reactants for the preparation of t-butyl ethyl ether by Williamson synthesis.
The Williamson ether synthesis is an organic reaction, forming an ether from an organohalide and a deprotonated alcohol (alkoxide). The correct pair of reactants used for the preparation of tert-butyl ethyl ether are sodium tert-butoxide and ethyl bromide.
Williamson reaction: $$ R-{ O }^{ - }+{ R }^{ ' }-X\longrightarrow R-O-{ R }^{ ' }+{ X }^{ - } $$
Explain how Alcohols of lower molecular mass are soluble in water.
Alcohols of lower molecular mass have the ability to form hydrogen bonds with water molecule, thereby solubilises in water.
But as the number of alkyl chain increases, the hydrophobic part hinders H-bonding and thus decreases the solubility of higher alcohols in water.
Write two methods of preparation of methyl alcohol. Describe giving diagram. Give such a test of methyl alcohol which is not given by ethyl alcohol which is not given by ethyl alcohol. Give the chemical reactions.
$${C_6}{H_5}Cl\xrightarrow[High\,\,temperature\,\, and\,\, pressure]{NaOH}A \xrightarrow{HCl}B$$
Identify $$A$$ and $$B$$ in the above reaction.
a) Write the mechanism of acid catalysed dehydration of ethanol to ethene.
b) Between phenol and alcohol which is more acidic? Why?
a. (Ref. image)
b. Phenol is more acidic than alcohol, because phenoxide ion is resonance stabilized where as alkoxide is not resonance stabilized. In case of alkoxide ion, the negative charge is localised on O atom whereas in case of phenoxide ion, the negative charge is localised on benzene ring. Hence, phenoxide ion is more stable than alkoxide ion.
Note: In case of phenol, the resonance leads to charge separation. Hence, phenol is less stable than phenoxide ion.
Complete the following reaction
Propene $$\xrightarrow[H_2O, \Delta]{H_2SO_4} A$$
Name the following
(1) Thte non-sublimable solid from a mxiture of iodine and potassion nitrate.
(2) The heavier liquid component from -mercury and water
(3) The lower boiling point component from methyl alcohol and water.
(4) The compound containing one atom of sulphur and two atoms of oxygen
(5) An acid whose formula is $${H}_{2}{CO}_{3}$$
Explain the following behaviours :
(i) Alcohols are more soluble in water than the hydrocarbons of comparable molecular masses.
(ii) Ortho-nitrophenol is more acidic than ortho-methoxyphenol.
(iii) Cumene is a better starting material for the preparation of phenol.
Write the IUPAC name of the compound in the picture.
Alcohols are named by adding $$-ol $$ to the parent alkone name e is replaced by $$ol$$ in parent alkane name.
Ref. image
1-Benzyl -3, 3 - dimethyl prop-en - 3 - ol$$
How will you prepare the compounds from benzene ? You may any inorganic regent and any organic reagent having not more than carbon atom
Phenylacetic acid
Refer Image-1
:- Can be achieved by following Rxn:-
(1) friedel craft alkylation
(2) Bromination or chlorination
(3) Nucleophilic substitution Rxn with alc. KCN
(4) Hydrolysis in $$H^{\oplus}$$
Refer Image-2
Discuss the mechanism of the following reactions:
(A) Dehydration of alcohols to form alkenes.
The dehydration of alcohol to form alkene occurs in three steps.
First step: Formation of protonated alcohol. Alcohol acts as weak base because of the presence of two lone pairs of oxygen. They undergoes reaction with strong acid like $$HCl$$ to form oxonium salt.
Second step: Carbocation formation. Protonated alcohol eliminates molecule of water to form ethyl carbocation.
Third step: Proton elimination to form ethene. Being reactive in nature, ethyl carbocation readily loses a proton to form ethene molecule.
Complete the following equation.
$$H-\overset{\overset{\displaystyle O}{||}}{C}-OEt+2CH_3CH_2MgI\overset{H_2O/H^+}{\rightarrow}(A)$$.
Ester on reaction with Grignard reagent (excess) also forms alcohol. First carbonyl compound (ketone or aldehyde) is formed from ester and Grignard reagent, and then further reacts with second molecule of Grignard reagent to form alcohol.
Arrange the following in decreasing order of rate of dehydration with conc. $$H_2SO_4$$:
(A) $$CH_3CH_2CH(OH)CH_2CH_2CH_3$$
(B) $$(CH_3)_2C(OH)CH_2CH_2CH_3$$
(C )$$(CH_3)_2C(OH)CH(CH_3)_2$$
(D) $$CH_3CH_2CH(OH)CH(CH_3)_2$$
(E) $$CH_3CH_2CH_2CH_2CH_2CH_2CH_2OH$$
Dehydration of alcohols with Conc. H2SO4 follows elimination
mechanism.Stability of α- Carbocation would be the order of
dehydration as well as formation of more substituted alkene
favours the dehydration reaction.
By considering all mechanism shown in figure, the order will be:
C > B > D > A > E .
Complete the following equation.
$$RCH=CH_2\overset{Hg(OAc)_2}{\underset{THF, -H_2O}{\rightarrow}}(A)\overset{NaBH_4}{\rightarrow}(B)$$.
Hydrolytic addition of mercuric acetate to an alkene followed by
demercuration is used for the hydration of alkenes under mild
conditions ;It obeys Markownikoff’ rule . Hence this is a useful
alternative to the hydroboration / oxidation sequence which leads ,
overall , to ‘anti-Markownikoff’ hydration . The Reaction was initially
called ‘Oximercuration’.
Alkenes are hydrated by treatment with mercury diacetate in amixture
of THF and water to give the hydoxyalkylmercury acetate which is
demercurated with alkaline NaBH4.
Step1:
On the treatment of Hg(OAc)2 and THF.
RCH=CH2 → RCH(OH)CH2HgOAc
Step 2:
Then on treatment with alkaline NaBH4
RCH(OH)CH2HgOAc → RCH(OH)CH3
Since, COMPOUND A is RCH(OH)CH2HgOAc
COMPOUND B is RCH(OH)CH3
Complete the following equation.
Answer the following.
What is the name of carbinol?
Outline a synthesis of alcohol from the indicated starting material.
$$1$$-Phenylethanol from styrene(vinyl benzene).
Addition of water takes place across double bond according to Markonikov's rule.
How will you obtain?
Ethanol from acetylene.
Show, how would you synthesize the following alcohol from appropriate alkene?
The alkene for synthesising the alcohols can be obtained by frst dehydrating the alcohol to give either a single alkene or a mixture of alkenes. If a mixture of alkenes is possible then find out which alkene gives the desired alcohol. The acid catalysed addition of $$H_2O$$ to alkenes occurs in accordance with the Markownikoff's rule.
Show, how would you synthesize the following alcohol from appropriate alkene?
Show, how would you synthesize the following alcohol from appropriate alkene?
Show, how would you synthesize the following alcohol from appropriate alkene?
The alkene for synthesising the alcohols can be obtained by frst dehydrating the alcohol to give either a single alkene or a mixture of alkenes. If a mixture of alkenes is possible then find out which alkene gives the desired alcohol. The acid catalysed addition of $$H_2O$$ to alkenes occurs in accordance with the Markownikoff's rule
Give reasons for the following.
Hydration of $$3$$-phenylbut-$$1$$-ene in dil. $$H_2SO_4$$ forms $$2$$-phenylbutan-$$2$$-ol instead of $$3$$-phenylbutan-$$2$$-ol.
Hydration gives an intermediate $$2^oC^+$$, which undergoes a hydride shift to more stable $$3^o$$ carbocation.
Give the major product of hydration of the following alkene.
Write down the dehydration product of the following.
Removal of water is nothing but dehydration.
Dehydration follows Saytzeff's rule.
More substituted alkene is major product
Dehydration follows Saytzeff's rule.
More substituted alkene is major product
Give the major product of hydration of the following alkene.
Write down the dehydration product of the following.
Removal of water is nothing but dehydration.
Dehydration follows Saytzeff's rule.
More substituted alkene is major product
Write down the dehydratiom product of the following.
Removal of water is nothing but dehydration.
Dehydration follows Saytzeff's rule.
More substituted alkene is major product
Convert the following:
Toluene to benzyl alcohol
Complete the above :
For finding (B), we proceed reverse to obtain (B)
Reverse Reaction:Refer image,
So, (B) is Butanal.
Convert the following
Identify the major and minor products.
Write the structural formula for each of the following.
Three $$1^{\circ}$$ alcohols with the formula $$C_{4}H_{8}O$$.
Why is there a large difference in th boiling points of butanal and butan-1-ol?
Butanol has polar O-H bond due to which it shows intermolecular H-bonding which is not possible in case of butanal due to absence of polar bond. Hence, butanal has a higher boiling point than butan-1-ol.
Which of the following is the correct method for synthesising methyl-t-butyl ether and why ?
$$i$$. $$(CH_{3})_{3}CBr + NaOMe\rightarrow$$
$$ii$$. $$CH_{3}Br + NaO-t-Bu\rightarrow$$
Give Reason for the following in one or two sentences.
'Acid-catalysed dehydration of t-butanol is faster than that of n-butanol'.
The mechanism for the hydrolysis of t-butanol and n-butanol are:
From the above mechanisms, it is clear that t-Butanol gives stable $$3^{o}C^{\oplus}$$, whereas n-butanol gives $$1^{o}C^{\oplus}$$. So the dehydration of t-butanol is faster than that of n-butanol.
Give reasons for the following:
Alcohols are more soluble in water than the hydrocarbons of comparable molecular masses.
Complete the following reaction.
The reaction exhibits azo-coupling of phenols. In mild alkaline conditions, phenol moiety participates in the azo-coupling, and para position of phenol is occupied.
Complete each synthesis by giving missing starting material, reagent or products:
What is the order of dehydration of primary, secondary and tertiary alcohols?
How will you convert:
Propene to Propan-1-ol?
Arrange the following compounds in increasing order of acidity and give a suitable explanation. Phenol, o-nitrophenol,o-cresol.
Preperation of alcohols from alkenes involves the electrophilic attack on alkene carbon atom. Explain its mechanism.
How can propan-2-one be converted into tert-butyl alcohol?
Explain why is $$ O=C=O $$ nonpolar while $$ R-O-R $$ is polar.
Ethers can be prepared by Williamson's synthesis in which an alkyl halide is reacted with sodium alkoxide. Di-tert-butyl ether can't be prepared by this method. Explain.
Explain why alcohols and ethers of comparable molecular mass have different boiling points
Alcohols react with active metals e.g. Na, K etc. to give corresponding alkoxides. Write down the decreasing order of reactivity of sodium metal towards primary. secondary and tertiary alcohols.
Explain why nucleophilic reactions are not very common in phenols.
Give three methods of preparation of anisole.
Identify if phenol is insoluble, partially soluble or highly soluble in water?
Write the equation of the reaction of hydrogen iodide with:
Methoxy benzene
Alcohols are soluble in water whereas diethyl ether is not, explain with reason.
The solubility of alcohol in water is due to excessive intermolecular hydrogen bonding in their molecules. The extent of hydrogen bonding in diethyl ether is less as compared to alcohols. Therefore diethyl ether is soluble in water only to a small extent.
Show how you will synthesise:
$$1$$-phenylethanol from a suitable alkene.
How would you distinguish experimentally between primary alcohol and a carboxylic acid?
The carbon-oxygen bond in phenol is slightly stronger than that in methanol. Why?
Write the equation of the reaction of hydrogen iodide with:
Benzyl ethyl ether.
How will you prepare the following from chloroform?
$$HC(OC_2H_5)_3 $$
Give the mechanism of dehydration of alcohols.
The mechanism of acid dehydration of ethanol to yield ethene is shown above.
First step is the protonation of oxygen atom of −OH group.
Second step is the loss of a molecule of water to form carbonium ion.
Last step is deprotonation to form carbon carbon double bond.
Class 12 Engineering Chemistry Extra Questions
- Alcohols,Phenols And Ethers Extra Questions
- Aldehydes,Ketones And Carboxylic Acids Extra Questions
- Amines Extra Questions
- Biomolecules Extra Questions
- Chemical Kinetics Extra Questions
- Chemistry In Everyday Life Extra Questions
- Coordination Compounds Extra Questions
- Electrochemistry Extra Questions
- General Principles And Processes Of Isolation Of Elements Extra Questions
- Haloalkanes And Haloarenes Extra Questions
- Polymers Extra Questions
- Solutions Extra Questions
- Surface Chemistry Extra Questions
- The D-And F-Block Elements Extra Questions
- The P-Block Elements Extra Questions
- The Solid State Extra Questions