MCQ Questions for Class 12 Engineering Chemistry Alcohols,Phenols And Ethers Quiz 2

Which one of the following compounds has the most acidic nature?

The major product obtained in the reaction $C{H_3}C{H_2}C \equiv CH\xrightarrow[{{H_2}O}]{{H{g^{ 2 + }},{H_3}{O^ + }}}$ is:

0%
$CH_3CH_2CH_2CH(OH)_2$
0%
$CH_3CH_2CH = CHOH$
0%
$CH_3CH_2CH_2CHO$
0%
$CH_3CH_2COCH_3$

Which of the following is used as freezing mixture?

0%
Mixture of ether and liquid $CO_{2}$
0%
Mixture of ether and ethyl alcohol
0%
Mixture of ether and dry ice
0%
Mixture of ethyl alcohol and dry ice

Alcohols containing only up to ___________ carbon atoms are completely miscible with water.

0%
three
0%
four
0%
five
0%
two

The IUPAC name for

$CH_3CH(OH)CH_2C(CH_3)_2OH$ is:

0%
1, 1-dimethyl-1,3-butanediol
0%
2-methyl-2,4 pentanediol
0%
4-methyl-2 4-pentanediol
0%
1,3,3- trimethyl 1-1,3-propanediol

The IUPAC name of

$CH_{3} - C(CH_{3}) (OH) CH_{2} - CH (CH_{3})_2$ is:

0%
2,4-Dimethylpentan-2-ol
0%
2,4-dimethylpentan-4-ol
0%
2,2-dimethylbutane
0%
2,4,4-trimethylbutan-2-ol

Explanation

In the longest carbon chain,

$-OH$ group is closest to the left-hand side, therefore we number from the left-hand side. There is 5 carbon in the longest chain, in second and fourth positions methyl group is attached and in second position there is an alcoholic group. Thus IUPAC name is 2,4-Dimethyl pentan-2-ol.

Identify the final product in the following sequence of reactions.

0%
$CH_3CH(CH_{(c)})COOH$
0%
$CH_3CH_2CH_2CH_2OH$
0%
$CH_3CH_2CH_2COOH$
0%
$CH_3CH_2COOH$

Trivial name of methanol is _________ .

0%
wood spirit
0%
methyl alcohol
0%
wood alcohol
0%
all of the above

__________ is prepared on a large scale from water gas.

0%
Methanol
0%
Ethanol
0%
Methane
0%
Ethane

Explanation

Methanol is prepared on a large scale from water gas.
Water gas is an equimolar mixture of

$\displaystyle CO$ and

$\displaystyle H_2$ . Water gas is heated with hydrogen (2:1 ratio) in presence of catalyst to form methanol.

$\displaystyle \underset { \displaystyle \text { synthetic gas } }{ \underset { \displaystyle \text { Water gas } }{ CO+H_2 } }+H_2 \xrightarrow [ 300^oC \text { under pressure}]{Cr_2O_3 -ZnO} CH_3-OH$

What is the IUPAC Name of t-butyl alcohol?

0%
Butan-2-ol
0%
2-Methyl-propan-2-ol
0%
Butan-1-ol
0%
Propan-2-ol

Identify E :

IUPAC name of the compound

$CH_3-CH(CH_2CH_3)-CH_2-CH(OH)-CH_3$ is:

0%
4-Ethyl-2-pentanol
0%
4-Methyl-2-hexanol
0%
2-Ethyl-2-pentanol
0%
3-Ethyl-2-hexanol

The name of the compound :

0%
Pentan-1-ol
0%
Pentan-2-ol
0%
Pentan-4-ol
0%
None of these

On treatment with dilute

$H_{2}SO_{4}$ , ethene forms ethanol.

Is the above statement true?

0%
True
0%
False

Which of the following is used in the manufacture of ethanol?

0%
$C_{2} H_{6}$
0%
$C_{2}H_{2}$
0%
$CH_{4}$
0%
$C_{2}H_{4}$

Explanation

Alcohols can be prepared by the hydration of alkenes. Therefore, ethanol(

$C_{2}H_{5}OH$ ) can be prepared from the corresponding alkene;

$C_{2}H_{4}$ as:

$CH_{2}=CH_{2} + H_{2}O \overset{H^{+}}{\rightarrow} CH_{3}CH_{2}OH$

Which of the following products are formed when ethyl alcohol is heated with

$H_{2}SO_{4}$ ?

0%
Ethene
0%
Diethyl ether
0%
Dimethyl ether
0%
Ethane

Explanation

Ethyl alcohol when heated in the presence of dil.

$H_{2}SO_{4}$ gives Ethyl ether as:

$2CH_{3}CH_{2}OH \xrightarrow[140C^{\circ}]{H_{2}SO_{4}} C_{2}H_{5}-O-C_{2}H_{5} + H_{2}O$
If ethyl alcohol is heated at higher temperature , ethene is formed as:

$C_{2}H_{5}OH \xrightarrow[170^{\circ}C]{H_{2}SO_{4}} CH_{2}= CH_{2} + H_{2}O$

Decolorization of

$KMnO_4$ solution takes place when it reacts with ethene. The final product of this reaction which is used as anti-freeze is:

0%
ethylene glycol
0%
propylene glycol
0%
ethanol
0%
propanol

Explanation

Hydroxylation of ethene takes place in the presence of cold

$KMnO_{4}$ to form Ethylene glycol. The reaction can be written as:

$CH_{2}= CH_{2} \xrightarrow[25^{\circ}C]{MnO_{4}^{2-}} HOCH_{2}-CH_{2}OH + MnO_{2}$

$CH_3CH = CHCH_3 \xrightarrow [(i)A]{(ii) B} CH_3-\underset{OH}{\underset{|}{C}H} - \overset{OH}{\overset{|}{C}H} - CH_3$ ,

$A\& B$ are

How would you get racemic mixture of 1, 2-butane diol from cis 2- butene?

0%
$\displaystyle A=KMnO_{4}/OH^{-}, B=H_{2}O$
0%
$\displaystyle A=CF_{3}/CO_{3}H, B=H_{2}O$
0%
$\displaystyle A=OsO_{4}/OH^{-}, B=H_{2}O$
0%
$\displaystyle A=O_{3}/H_{2}O, B=Ph_{3}P$

By treating alkylchloride with aq.

$KOH$ produce:

0%
alcohol
0%
$KCl$
0%
alkane
0%
Both $A$ and $B$

Explanation

In the presence of aqueous

$KOH$ , alkyl chloride gives the substitution product as alcohol. The reaction can be written as:

$RCl + KOH(aq) \rightarrow ROH + KCl$

In the production of alcohol _____ are used.

0%
alkene
0%
alkynes
0%
alkanes
0%
both (a) and (b) above

Explanation

Hydration of alkene:

In this process, concentrated

$H_2SO_4$ is treated with alkene at room temperature to produce alkyl hydrogen sulphide. After addition of

$H_2O$ and heated it, alkyl hydrogen sulphate hydrolysis to alcohol.

IUPAC name is 3-phenylpropan-1-ol.

0%
True
0%
False

Dehydration of alcohols take place more rapidly with

$\displaystyle POCl_{3}$ than with

$\displaystyle H_{2}SO_{4}.$

Select the correct statements(s) about the above dehydration reaction :

0%
It does not involve carbocation.
0%
It involves $\displaystyle R-OPOCl_{2}$ with $\displaystyle -OPOCl_{2}$ as a better leaving group.
0%
It involves $E2$ mechanism as pyridine base abstracts proton from the adjacent carbon as the same time at which $\displaystyle -OPOCl_{2}$ is leaving.
0%
It is $E1$ reaction without formation of carbocation.

Explanation

1. Nucleophilic attack and deprotonation.

$E-2\quad \beta -$ Hydrogen elimination.

Hence the correct options are A, B and C.

1157025_137125_ans_b7f6c59cb8c0473b91051abea3197990.png

Ethanol on reaction with acetic anhydride gives:

0%
acetic ester
0%
formic ester
0%
ethanoic acid
0%
ethyl acetate and ethanoic acid

Explanation

The reaction of acetic anhydride with ethanol yields ethyl acetate and ethanoic acid.

$(CH_3CO)_2O + CH_3CH_2OH \rightarrow CH_3COOCH_2CH_3 + CH_3COOH$

IUPAC name is 1-phenyl propan-3-ol.

Is the above statement correct?

0%
True
0%
False

Compound which gives alcohol on reduction is/are:

Explanation

Acid chlorides, Epoxides and Acid anhydrides on reduction with

$LiAlH_4$ forms alcohol as end product. Only Acid amides when reduced form amines.

$CH_3CONH_2\overset{LiAlH_4}\rightarrow CH_3CH_2NH_2$
Therefore, Options A, C and D are correct.

What is IUPAC name of the following compound?
C

$H_3$ - C

$H_2$ - C

$H_2$ - OH

0%
Propane-1-ol
0%
Propane-2-ol
0%
Ethane-1-ol
0%
Ethane-2-ol

Explanation

${ CH }_{ 3 }^{ 3 }{ CH }_{ 2 }^{ 2 }{ CH }_{ 2 }^{ 1 }{ OH }$
Carbon with functional group gets position 1. Therefore, IUPAC name is Propan-1-ol.

$\displaystyle EtO-CH_2-C_6H_5+HI\rightarrow D$

Name the product D in the given reaction.

0%
Diethyl ether
0%
Benzyl iodide
0%
ethane
0%
none of these

Which of the following has a higher boiling point?

0%
Butanol
0%
Butanal
0%
Both of them have similar boiling point
0%
Cannot say anything

The following structures represents cyclopentyl methyl carbinol.

State whether the given statement is true or false:

0%
True
0%
False

Explanation

The IUPAC name of the above compound is 1-Cyclopentylethanol but the group (

$CH_3OH$ ) is commonly called as carbinol therefore the the above compound can also be named as cyclopentyl methyl carbinol.

Number of 1,2-hydride shifts occur while converting

$1-$ methylcyclohexanol to

$1-$ bromo

$-1-$ methylcyclohexane is:

0%
1
0%
0
0%
2
0%
3

Among the three isomers of the nitrophenol, the one that is least soluble in water is:

0%
m-nitrophenol
0%
o-nitrophenol
0%
p-nitrophenol
0%
none of these

Acid-catalysed dehydration of which of following compounds is fastest?

0%
t-Butanol
0%
sec-Butanol
0%
n-Butanol
0%
All dehydrate at similar rate

Explanation

These compounds who formed more stable carbocation undergo acid-catalyzed dehydration fastly. Hence,

$t-Butanol$ from tertiary carbocation which has

$9- \alpha$ hydrogen undergo fast acid - catalyzed dehydration.
1051147_247006_ans_02155ee9d1184b27a370e08d01e90147.PNG

The

$-OH$ group in alcohols can be replaced by:

0%
$\displaystyle SOCl_{2}$
0%
$\displaystyle Cl_{2}$
0%
$\displaystyle PCl_{5}$
0%
$\displaystyle P+Cl_{2}$

Explanation

$2P + 3Cl_2 \rightarrow 2PCl_3$ and

$PCl_3$ can also replace the

$-OH$ group in alcohol.

$CH_3-\underset{CH_3}{\underset{|}{C}H}-\underset{OH}{\underset{|}{C}H}-\underset{CH_3}{\underset{|}{\overset{CH_3\!\!\!\!\!}{\overset{|}{C}}}-}CH_3$

The IUPAC name of the above given compound is:

0%
2,2,4-Trimethylpentan-3-ol
0%
2,4,4-trimethylpentan-3-ol
0%
2-methyl-1-(2-methylpronyl)-propanol
0%
none of the above

Explanation

$\overset{5}CH_3-\underset{CH_3}{\underset{|}{C}\overset{4}H}-\underset{OH}{\underset{|}{\overset{3}C}H}-\underset{CH_3}{\underset{|}{\overset{CH_3\!\!\!\!\!}{\overset{2|}{C}}}-}\overset{1}CH_3$

The compound has 2 methyl groups at carbon number 2 and one methyl group at carbon number 4.

Functional group

$-OH$ (ol) is attached at carbon number 3

So its name is 2, 2, 4-Trimethylpentan-3-ol.

Option A is correct.

IUPAC name of the given compound is:

0%
5-ethylheptane-2.4-diol
0%
3-ethylheptane-4,6-diol
0%
4-ethyl-1-methylhexane-1,3-diol
0%
none of these

Explanation

The compound have ethyl group at carbon no

$5$ , two hydroxyl groups at carbon no

$2$ and

$4$ . So its name is

$5-$ ethylheptane

$-2.4-$ diol.

Acid-catalysed dehydration of which of following compounds is slowest?

0%
t-Butanol
0%
sec-Butanol
0%
n-Butanol
0%
All of them dehydrate at similar rate

Explanation

Compounds which form less stable carbocation undergo slow dehydration or we can say primary carbocation. Hence,

$n-Butanol$ form primary carbocation which is less stable, so undergo slow dehydration.
1051136_247011_ans_563d6da2d6e043cf96d0d45dafc05a30.PNG

1051136_247011_ans_563d6da2d6e043cf96d0d45dafc05a30.PNG

Which of the following is wood alcohol?

0%
$\displaystyle CH_{3}OH$
0%
$\displaystyle C_{2}H_{5}OH$
0%
1-Butanol
0%
2-Methyl -1-propanol

Explanation

Methanol, also known as methyl alcohol, wood alcohol, wood naphtha, methyl hydrate, or wood spirits, is a chemical with the formula CH₃OH.

Methanol acquired the name wood alcohol because it was once produced chiefly by the destructive distillation of wood

Hence, the correct option is

$\text{A}$

Which of the following statements is/are correct?

0%
PhOH has a higher boiling point than PhSH (benzenethiol)
0%
p-Hydroquinone has a higher melting point than catechol.
0%
o-Nitrophenol has a lower boiling point than m-and p-isomers.
0%
o-Hydroxybenzaldehyde is more water solube than m-and p-isomers

Explanation

A. PhOH has higher boiling point due to H-bonding.
B. Molecules of p-benzoquinone can fit closer in solid state causing it to have higher melting point.
C. & D. Intramolecular H-bonding (chelation) in the o-isomers inhibits the intermolecular attraction, lowers the boiling point, reduces H-bonding with

$\displaystyle H_{2}O$ and decreases water solubilities. Intramolecular chelation does not occur in meta and para-isomers.

Option A, B and C are correct.

$CH_3-\underset{OH}{\underset{|}{C}H}-\underset{OH}{\underset{|}{C}H}-CH_3$

IUPAC name of the given compound is :

0%
Butane-2,3-diol
0%
1-Methyl-propane-1,2-diol
0%
Both (A) and (B)
0%
None of these

Explanation

Two functional group

$OH (ol)$ is attached at carbon no

$2$ &

$3$ so its name is butane

$-2,3-$ diol.

Which of the following is produced during the following reaction?

$\displaystyle CO\left ( g \right )+H_{2}\left ( g \right )\xrightarrow[ZnO,Cr_{2}O_{3}]{575 K}$

0%
Ethanol
0%
Ethanal
0%
Methanol
0%
Methanal

Explanation

Methanol is produced during the following reaction

$\displaystyle CO\left ( g \right )+H_{2}\left ( g \right )\xrightarrow[ZnO,Cr_{2}O_{3}]{575 K} CH_3OH$ .

A mixture of CO and hydrogen (1:2 molar ratio) is called synthetic gas.

It is heated to a temperature of 573 K in presence of

$ZnO/ Cr_2O_3$ catalyst to form methanol.

It is industrial method of preparation of methanol.

Option C is correct.

In the synthesis of n-alkyl tert-alkyl ether by Williamson's method the reactants used are:

0%
$\displaystyle 3^{\circ}RX$ and $1^{\circ} RONa$
0%
$\displaystyle 1^{\circ}RX$ and $3^{\circ} RONa$
0%
$\displaystyle 3^{\circ}RX$ and $3^{\circ} RONa$
0%
$\displaystyle 1^{\circ}RX$ and $1^{\circ} RONa$

Explanation

In the synthesis of n-alkyl tert-alkyl ether by Williamson's method,

$\displaystyle 1^{\circ}RX$ and

$3^{\circ} RONa$ are used.
If

$\displaystyle 3^{\circ}RX$ is used, it will undergo dehydrohalogenation to form an alkene.

The IUPAC name of the following compound is:

0%
3-cyclohexylpentan-3-ol
0%
3-cyclohexyl,3-hydroxypentane
0%
3-hydroxypentyl cyclohexane
0%
none of the above

When 3-methylbutan-2-ol is treated with HBr, the following reaction takes place. What are the correct steps for formation of the above product?

0%
Formation of carbocation $\rightarrow$ Nucleophilic attack by $Br^\ominus$
0%
Formation of carbocation $\rightarrow$ 1,2 hydride shift $\rightarrow$ Nucleophilic attack by $Br^\ominus$
0%
Formation of carbocation $\rightarrow$ 1,2 methyl shift $\rightarrow$ Nucleophilic attack by $Br^\ominus$
0%
None of these

The IUPAC name of the following compound is:

0%
1-Phenylpropan-2-ol
0%
3-Phenylpropan-2-ol
0%
2-Hydroxypropylbenzene
0%
None of these

Explanation

The IUPAC name of the given compound is 1-Phenylpropan-2-ol.

The parent hydrocarbon contains 3 C atoms and is named as propane.

A hydroxyl group (

$-OH$ ) is present at second C atom.

Hence, the last alphabet e of propane is replaced with the suffix -2-ol.

A phenyl group is present as a substituent at first carbon atom.

$CH_3 - \underset{OH}{\underset{|}{\overset{CH_3}{\overset{|}{C}}}} - CH_2 - CH_3$

The correct IUPAC name of the above compound is:

0%
tert- amyl alcohol
0%
2-methylbutan-2-ol
0%
2-methylpentan-2-ol
0%
1,1 dimethyl propan-1-ol

Solubility of alcohols in water is _______ to that of hydrocarbons of comparable molecular masses.

0%
greater than
0%
similar
0%
lesser than
0%
none of these

Explanation

Since alcohols can participate in

$H-$ bonding while hydrocarbons cannot, alcohols are able to interact with water molecules more easily than hydrocarbons of comparable molecular masses. Hence alcohols possess greater solubility in water than hydrocarbons of comparable molecular masses.

The IUPAC name of the following compound is:

0%
1-cyclopentene-4-ol
0%
3-cyclopenten-1-ol
0%
3-hydroxy cyclopentene
0%
4-hydroxy cyclopentene

Lower alcohols are highly soluble in water due to _____.

0%
van der Waal's attraction
0%
dipole dipole interaction
0%
steric hindrance
0%
H-bonding

The product obtained in the above reaction is:

0%
0%
0%
$\displaystyle RCH=CHCOOH$
0%
none of these

Explanation

When

$\beta$ hydroxy acid is heated, it undergoes dehydration to form

$\alpha, \beta$ unsaturated acid.

$\displaystyle RCHOHCH_2COOH \xrightarrow [dehydration] {\Delta} RCH=CHCOOH$

Which of the following groups will increase the acidity of phenol?

0%
$-N{O}_{2}$
0%
$-CN$
0%
$-X$ (halogen)
0%
None of these

Explanation

$-N{O}_{2}$ ,

$-CN$ and

$-X$ (halogen) groups will increase the acidity of phenol. These are electron withdrawing groups and stabilize the negative charge of phenoxide ion. Due to this, the removal of proton becomes easy.

CBSE Questions for Class 12 Engineering Chemistry Alcohols,Phenols And Ethers Quiz 2 - MCQExams.com

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Practice Class 12 Engineering Chemistry Quiz Questions and Answers

CBSE Questions for Class 12 Engineering Chemistry Alcohols,Phenols And Ethers Quiz 2 - MCQExams.com

0:0:1

Practice Class 12 Engineering Chemistry Quiz Questions and Answers

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