1, 3, 3-trimethyl-1, 3-propanol

MCQ Questions for Class 12 Engineering Chemistry Alcohols,Phenols And Ethers Quiz 4

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

0%
10
0%
3
0%
8
0%
14

Explanation

Alcohol-containing up to

$3-$ carbon atoms are completely miscible with water in all proportions. This is due to the hydrogen bonding with water molecule.

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

0%
$C_2H_6$
0%
$C_2H_2$
0%
$CH_4$
0%
$C_2H_4$

Explanation

The correct option is D. Ethanol can be prepared by hydration of ethane in the presence of

$H_{ 2 }O.$
1171649_522790_ans_7637f2936f714b0fb6bd97f8242fdd75.PNG

The boiling point of 95% ethanol is higher than that of absolute ethanol.

0%
True
0%
False

Explanation

The correct option is

$B$ . Ethanol forms a constant boiling mixture or azeotrope with water that contains

$95$ % ethanol and

$5$ % water that boils below the pure alcohol.

The solubility of alcohols in water gradually increases with molecular weight.

0%
True
0%
False

The distillation of rectified spirit gives absolute ethanol.

0%
True
0%
False

Explanation

The distillation of the rectified spirit after the fractional distillation, it gives absolute ethanol which is

$100$ %

Which of the following can not be formed by hydrolysis of alkenes?

0%
Methanol
0%
Ethanol
0%
Propanol
0%
None of these

Melting point of phenol is:

0%
$95^0$ C
0%
$43^0$ C
0%
$20^0$ C
0%
$10^0$ C

Explanation

The correct option is

$B$ .

Phenol is crystalline solid and has a definite melting point at

$43$ degree Celsius.

1174683_568550_ans_7ef8ba50823d426eb6d0b9417ec30a31.PNG

In the reaction,

$C_2H_5OH \xrightarrow[300^oC]{Cu} X$ the molecular formula of X is:

0%
$C_4H_6O$
0%
$C_4H_{10}O$
0%
$C_2H_4O$
0%
$C_2H_6$

Explanation

${ C }_{ 2 }{ H }_{ 5 }OH$ , ethanol upon oxidisation with Cu followed by heating at

$300$ degree Celsius gives aldehyde with molecular

${ C }_{ 2 }{ H }_{ 4 }O.$
1038523_522794_ans_a2bc084e6bf4407fbdd73f97bedcc59a.PNG

Phenol reacts with alkali to give:

0%
salt
0%
water
0%
both A and B
0%
complex compound

Hydrogen chloride and

$SO_2$ are the side products in the reaction of ethanol with thionyl chloride. Which of the following is the main product in this reaction?

0%
$C_2H_5OC_2H_5$
0%
$C_2H_6$
0%
$CH_3Cl$
0%
$C_2H_5Cl$

Explanation

When ethanol is treated with thionyl-chloride, the side product are

$HCl$ and

$S{ O }_{ 2 }$ and main product is

${ C }_{ 2 }{ H }_{ 5 }Cl.$
1174964_522795_ans_68ce62c5060d4822a06facf6482759d5.PNG

What type of spectroscopy would be the best tool to analyze a clear and colorless solution for the presence of a functional group like an alcohol group

$(-OH)$ ?

0%
UV spectroscopy.
0%
IR spectroscopy.
0%
Mass spectroscopy.
0%
Photoelectron spectroscopy.

Phenol is a:

0%
crystalline solid
0%
amorphous solid
0%
volatile liquid
0%
nonvolatile liquid

What are X and Y respectively in the following reaction?

$\displaystyle X \xrightarrow[]{PBr_3} C_2H_5Br \xrightarrow[\Delta]{AgOH}Y$

0%
$CH_3OH, C_2H_6$
0%
$C_2H_5OH, C_2H_5AgBr$
0%
$CH_3COOH, CH_3CH_2OH$
0%
$C_2H_5OH, C_2H_5OH$

Explanation

Ethanol when treated with

${ PBr }_{ 3 }$ , it gives biomethane which on further treatment with

$AgOH$ gives back ethanol.
1172857_522792_ans_6044a9ce3157474cade31a8238129923.PNG

An industrial method for the preparation of methanol is:

0%
by catalytic reduction of carbon monoxide
0%
by reacting methane with steam in presence of a catalyst
0%
by reduction of $HCHO$ with $LiAlH_4$
0%
by reduction of $HCHO$ with aqueous $NaOH$

Explanation

An industrial method for the preparation of methanol is by catalytic reduction of carbon monoxide.

$\displaystyle \underset { \displaystyle \text { Synthetic gas } }{\underset { \displaystyle \text { water gas } }{CO+H_2}+H_2} \xrightarrow [ \text { 300 deg C, pressure }]{Cr_2O_3-ZnO} \underset { \displaystyle \text { Methanol } }{CH_3-OH}$

Methanol can be prepared when :

0%
iodomethane is heated with moist silver oxide
0%
iodomethane react with sodium in the presence of ether
0%
both A and B
0%
none of these

Explanation

Moist Silver oxide

$Ag_2O + H_2O \rightarrow 2AgOH$

$CH_3-I + AgOH \rightarrow CH_3-OH + AgI$

Therefore, methanol can be prepared when iodomethane is heated with moist silver oxide.

Reagents used for industrial preparation of methanol are:

0%
$CO+H_2$
0%
$HCHO+H_2$
0%
$CO_2+H_2$
0%
$HCOOH+H_2$

Explanation

Carbon monoxide and hydrogen react over a catalyst to produce methanol. Today, the most widely used catalyst is a mixture of copper and zinc oxides,supported on alumina.At

$5–10$ MPa (

$50–100$ atm) and 250 °C (482 °F), the reaction is characterized by high selectivity (

$>99.8$ %).

$CO + 2H_2 \longrightarrow CH_3OH$

Dehydration of alcohol is an example of which type of reaction?

0%
Substitution
0%
Elimination
0%
Addition
0%
Both $B$ and $C$

The IUPAC name of:

0%
2, 1-dimethyl-1, 3-butanol
0%
4,4-dimethyl-2-pentanol
0%
4-methyl-2, 4-pentanol
0%
1, 3, 3-trimethyl-1, 3-propanol

Explanation

The IUPAC name of the given compound is 4,4-dimethyl-2-pentanol.

The parent hydrocarbon contains 5

$C$ atoms and a

$-OH$ group. Hence, it is pentanol. Two methyl groups are present as substituents on fourth carbon atom and are named as the prefix. The prefix di indicates 2. The numbering is done from the end which gives the lowest locant to the

$C$ atom bearing

$-OH$ group.

Hence, the correct option is

$B$

Common name for methanol is:

0%
volemitol
0%
rubbing alcohol
0%
wood spirit
0%
xylitol

Which of the following compound is most acidic?

0%
$Cl-CH_2-CH_2-OH$
0%
0%
0%

Explanation

$NO_2$ shows

$-M$ effect as it placed on ortho group of phenol which stabilizes the phenoxide anion hence it will be most acidic.

Hence, option C is correct.

Destructive distillation of wood in the laboratory will result in the formation of :

0%
Ethanol
0%
Methane
0%
Methanol
0%
Butane

In Williamson's synthesis, ethoxy ethane is prepared by:

0%
heating sodium ethoxide with ethyl bromide
0%
passing ethanol over heated alumina
0%
treating ethyl alcohol with excess of conc. $H_{2}SO_{4}$ at $430-440\ K$
0%
heating ethanol with dry $Ag_{2}O$

The other name for Syngas is:

0%
Producer gas
0%
Water gas
0%
Tear gas
0%
Fuel gas

Methanol is called as Marine Methanol beacuse:

0%
it is an essential compound for marine life
0%
it is mostly obtained from deep sea bed
0%
it is used as a marine fuel
0%
it serves as a signal indicator for big ships on burning

Methanol is a:

0%
yellow coloured liquid
0%
brown coloured liquid
0%
colourless liquid
0%
blue coloured liquid

Identify the correct set representing properties of Methanol.

0%
Colourless, volatile, poisonous, miscible
0%
Colourless, volatile, non-poisonous, miscible
0%
Colourless, volatile, poisonous, immiscible
0%
Colourless, non-volatile, poisonous, miscible

There are two samples

$A$ and

$B$ .

$A$ is Methanol and

$B$ is Ethanol. Both are heated both at the same rate in closed container separately. Which one is correct about the above test?

0%
At $60^0$ C, container $A$ and $B$ both have liquids in them
0%
At $80^0$ C, container $A$ and $B$ both have vapours in them
0%
At $70^0$ C, container $B$ has liquid and $A$ has vapours
0%
All the above

Explanation

Methanol has a boiling point of

$64.7^0$ C whereas ethanol has a boiling point of

$78.24^0$ C. So, all the statements are correct.

What is the

$IUPAC$ name of the following compound?

$CH_{3} - CH_{2} - CH_{2} - OH$

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

Explanation

In this compound, the number of carbon atoms is 3. So, the parent alkane is propane.

The functional group present is

$-OH$ i.e alcohol.

$-OH$ is present at the first carbon atom

Thus the IUPAC name is Propan - 1 - ol.

Which of the following order is true regarding the acidic nature of phenol?

0%
Phenol $>$ O -cresol $>$ O-nitrophenol
0%
Phenol $>$ O -nitrophenol $>$ O-cresol
0%
O-cresol $<$ phenol $<$ O- nitrophenol
0%
Phenol $<$ O-cresol $<$ O-nitrophenol

Which of the following compounds has lowest boiling point ?

0%
n-butyl alcohol
0%
Isobutyl alcohol
0%
Tert-butyl alcohol
0%
Sec-butyl alcohol

Among i-iii the boiling point follows the order.

0%
$ii < i < iii$
0%
$iii < ii < i$
0%
$i < ii < iii$
0%
$ii < iii < i$

Explanation

In (III) intermolecular H bonding takes place so its boiling point will be highest while in (II) intramolecular H bonding takes place.

$ii<i<iii$

Which of the following alcohol has highest solubility in water ?

0%
Tertiary butyl alcohol
0%
Secondary butyl alcohol
0%
Ethylene glycol
0%
Glycerol

When alkyl halide is heated with dry

${ Ag }_{ 2 }O$ , it produces:

0%
ester
0%
ether
0%
ketone
0%
alcohol

Explanation

Alkyl halide on reaction with dry silver oxide gives ether.

$\underset { Alkyl \ halide }{ 2RX } +{ Ag }_{ 2 }O\longrightarrow \underset { ether }{ R-O-R } +2AgX$

What is the formula of tertiary butyl acohol?

0%
$CH_{3} - CH(CH_{3}) - CH_{2} - OH$
0%
$CH_{3} - (CH_{2})_{2}OH$
0%
$CH_{3} - CH(OH) - CH_{2} - CH_{3}$
0%
$(CH_{3})_{3} C - OH$

Explanation

Is the formula of tertiary butyl alcohol as in it

$-OH$ group is attached to tertiary carbon.

Which of the following is most soluble in water ?

0%
n- butyl alcohol
0%
Iso-butyl alcohol
0%
Tertiary butyl alcohol
0%
None of the above

Dehydration of alcohol is an example of which type of reaction ?

0%
Substitution reaction
0%
Elimination reaction
0%
Rearrangement reaction
0%
Addition reaction

Explanation

Dehydration of alcohol is an example

$\beta$ -elimination. It involves the lose of two atoms/groups from adjacent carbon atoms.

$\underset{ethanol}{\overset{\beta }{CH_3}\overset{\alpha }{CH_2}OH} \overset{alc.KOH}{\rightarrow}\underset{ethene }{CH_2 = CH_2}$

Consider the given reaction:

$\displaystyle CH_3-CH=CH-CH_2-OH \overset{HBr}{\underset{S_N 1}{ \longrightarrow}} [P]$

In the given reaction the product

$[P]$ is:

0%
$CH_3-CH=CH-CH_2-Br$
0%
$CH_3 - \!\!\overset{\,\,\,Br}{\overset{|}{C}}\!\!H - CH = CH_2$
0%
$CH_2=CH-CH=CH_2$
0%
$CH_3 - \overset{\,\,\,Br}{\overset{|}{C}}\!\!H - CH_2 - CH_2 - OH$

Explanation

As the dehydration takes place through

$SN^1$ mechanism so the carbocation intermediate forms.

More stable carbocation gives major product.

The correct answer is

$B$ .

1155653_696609_ans_40b56bfff28d445484d900a178eb3743.png

In which of the following reactions of alcohol there is no cleavage of C-O bond ?

0%
Dehydration reaction of alcohol
0%
Oxidation reaction of alcohol
0%
Reduction reaction of alcohol
0%
Reaction of alcohol with phosphorus tribromide

Explanation

(a) Dehydration of alcohol
It involves cleavage of C-O bond.

(b) Oxidation of alcohol

$3^o$ alcohols generally do not undergo oxidation however in the presence of

$KMnO_4$ , cleavage of C-C bond takes place to give two acids in which C-O bond remains uncleaved.

$CH_3CH_2OH \overset{LiAlH_4}{\rightarrow} CH_3CH_3$
It involves cleavage of C-OH bond.

(d) Reaction with phosphorus tribromide

$CH_3CH_2OH \overset{PBr_3}{\rightarrow} CH_3CH_2Br$
It also involves cleavage of C-OH bond.

Thus, oxidation reactions of alcohol do not involve cleavage of C-O bond among the given reactions.

What is the hybridisation of carbon and oxygen in electronic structure of ether?

0%
$sp^{3}$ and $sp^{2}$
0%
$sp^{3}$ and $sp^{3}$
0%
$sp$ and $sp$
0%
$sp^{2}$ and $sp^{2}$

Explanation

$sp^{3}$ (4-bond pairs) and

$sp^{3}$ (2-bond pairs and 2-lone pairs) hybridisations of carbon and oxygen in the electronic structure of an ether.

Which is the only alcohol that can be prepared by the indirect hydration of alkene?

0%
Ethyl alcohol
0%
Propyl alcohol
0%
Isobutyl alcohol
0%
Methyl alcohol

Explanation

Alkene is treated with sulfuric acid to give alkyl sulphate esters. In the case of ethanol production, this step can be written:

$H_2SO_4 + C_2H_4 \rightarrow C_2H_5-O-SO_3H$

Subsequently, this sulphate ester is hydrolyzed to regenerate sulphuric acid and release ethanol:

$C_2H_5-O-SO_3H + H_2O \rightarrow H_2SO_4 + C_2H_5OH$

This two step route is called the "indirect process".

Only in case of ethane it will produce ethyl alcohol while in case of other alkenes product is according to

$Markovnikov's\ Rule$ .

Methyl alcohol can't be produced by indirect hydration of alkene.

Which of the following statement is not correct ?

0%
Phenol is neutralised by sodium carbonate
0%
Phenol is used to prepare analgesic drugs
0%
Solubility of phenol in water is more than that of chlorobenzene
0%
Boiling point of o-nitrophenol is lower than that of p-nitrophenol

Explanation

Phenol does not react with

$Na_2\, CO_3$ because it is weaker acid than carboxylic acid and thereby do not have the strength to substitute or give away its H+ ions to that of weak bases like sodium carbonate.

Phenol is used for the preparation of aspirin which is used as an analgesic as well as antipyretic drugs.

Phenol is more soluble in water than chlorobenzene due to formation of H-bond with water molecules.

o-nitrophenol form intramolecular

$H-$ bonding while p-nitrophenol form intermolecular

$H-$ bonding. Due to this, nature o-nitrophenol has a lower boiling point than p-nitrophenol.

Which of the following represents monohydric alcohol?

0%
$C_nH_{2n}OH$
0%
$C_nH_{2n+1}OH$
0%
$C_nH_{n}O$
0%
$C_nH_{n}OH$

In the above reaction, the product

$(X)$ is:

Which of the following compounds decolourizes aqueous bromine and gives white fumes of

$HCl$ on reaction with

$PCl_{5}$ ?

0%
$CH_{3}COCH_{2}CH - CH_{2}$
0%
$CH_{3}CH_{2}CH_{2}CH_{2}CH_{3}$
0%
$CH_{3}CH = CHCH_{2}CH_{2}OH$
0%
$CH_{3}OCH_{2}CH_{2}CH_{2}CH_{2}OH$

Explanation

$CH_3-CH=CH-CH_2-CH_2-OH+PCl_5\longrightarrow K_3C-CH=CH-CH_2-CH_2-Cl+MCl+POCl_3$

$\downarrow$

$Br_2|H_2O$

Colour decolorises due to the presence of double bond.

An alcohol of molecular formula

$C_5H_{14}OH$ on dehydration gives an alkene, which on oxidation yields a mixture of ketone and an acid. The alcohol is:

0%
$CH_3CH_2CH(OH)CH_2CH_3$
0%
$CH_2-\underset{\underset{OH}{|}}CHCH_2CH_2CH_3$
0%
$(CH_3)_2CHCH(OH)CH_3$
0%
$(CH_3)_3CCH_2OH$

$A$ and

$B$ respectively are:

The order of reactivity of the following alcohols towards conc.

$HCl$ is:

0%
$I> II> III> IV$
0%
$I> III> II> IV$
0%
$IV> III> II> I$
0%
$IV> III> I> II$

Which one of the following phenols is the strongest acid?

Explanation

This is the strong acid because its conjugate base i.e phenolate ions is stabilished by the

$-H$ effect of

$-NO_2$

1172575_770064_ans_762cf84169f84e4db5c402e74de30b95.PNG

Among the compound I-IV, the compound having the lowest boiling point is

0%
I
0%
II
0%
III
0%
IV

Explanation

Alcohols have

$R-OH$ group, therefore can form intermolecular H-bonds with another alcohol molecule as shown in the figure. But an ether (

$R-O-R'$ ) has no

$H$ attached to

$O$ , therefore can not undergo intermolecular H-bonding and thus will have lowest boiling point among alcohols.

Hence, option

$C$ is correct.

The IUPAC name for the compound given below is:

0%
$(2R, 3Z)$ - 7 - phenylhept - 3- en - 2 - ol
0%
$(2S, 3Z)$ - 7 - phenylhept - 3- en - 2 - ol
0%
$(2R, 3E)$ - 7 - phenylhept - 3- en - 2 - ol
0%
$(2S, 3E)$ - 7 - phenylhept - 3- en - 2 - ol

CBSE Questions for Class 12 Engineering Chemistry Alcohols,Phenols And Ethers Quiz 4 - MCQExams.com

0:0:1

Practice Class 12 Engineering Chemistry Quiz Questions and Answers

CBSE Questions for Class 12 Engineering Chemistry Alcohols,Phenols And Ethers Quiz 4 - MCQExams.com

0:0:1

Practice Class 12 Engineering Chemistry Quiz Questions and Answers

Support mcqexams.com by disabling your adblocker.