CBSE Questions for Class 12 Engineering Chemistry Alcohols,Phenols And Ethers Quiz 10 - MCQExams.com

$$A\:(C_7H_8O)+Na/\Delta\longrightarrow$$ No gaseous product
$$A+Br_2/FeBr_3\longrightarrow\:C_7H_7OB_r$$ (Two isomers) 
$$A$$ can be:
 $$C(CH_3)_2=C(CH_3)_2\xrightarrow[H_2O]{Cl_2} A\xrightarrow[]{OH^-} B$$
The compound $$B$$ is:
  • $$(CH_3)_2\underset{OH}{\underset{|}{C}-} \underset{Cl}{\underset{|}{C}} (CH_3)_2$$
  • $$(CH_3)_2\underset{OH}{\underset{|}{C}-} \!\!\underset{\,\,OH}{\underset{|}{C}} \!\!(CH_3)_2$$
  • none of the above
The compound $$A$$ and $$B$$ are :
124157_bbee0e1877a24525bf8b0572e7448693.png
  • None of the above
Identify the structure of A:
  • $$CH_3 - CH_2 - CH_2 - \underset{\!\!\!OH}{\underset{\!\!\!\!\!\!|}{CH}} - CH_3$$
  • $$(CH_3)_2CHCHOHCH_3$$
  • $$(CH_3)_3C-CH_2-OH$$
  • $$CH_3 - CH_2 - \underset{\!\!\!OH}{\underset{\!\!\!\!\!|}{CH}} - CH_2 - CH_3$$
Which of the following reaction is most exothermic?
  • $$\overset{\bullet}{C}H_3 + CH_3CH_2CH_3 \rightarrow CH_4 + CH_3 \overset{\bullet}{C}HCH_3$$
Which of the following will be the correct product (P) for the given reaction?
117502_50f9149ed1b14776b738c252fd421d18.png

The addition of mercuric acetate in the presence of water is called oxymercuration. The adduct obtained gives alcohol on reduction with $$NaBH_4$$ in alkaline medium. This is known as demercuration. Oxymercuration-demercuration allows Markownikoff's addition of H, OH without rearrangement. The net result is the addition of $$H_2O$$. 
Based on the above information, find product A in the given reaction.

117531_d9ead791051544a3868b5076e0b73290.png

Give the expected major product of the above reaction.

122697_a9edf726838e49c7a5c020ffbcaf5e04.png
Which of the following reagents should be used to prepare tert-butyl ethyl ether?
  • $$tert$$-butyl bromide and sodium ethoxide
  • $$tert$$-butyl alcohol and ethyl bromide
  • $$tert$$-butyl alcohol and ethanol
  • potassium $$tert$$-butoxide and ethyl bromide
Select schemes A, B, C out of the given below.
I. Acid catalysed hydration  
II. Hydroboration oxidation
III. Oxymecruation-demercuration

124170.png
  • I in all cases
  • I, II, III
  • II, III, I
  • III, I, II
What is $$A$$ ?

205850.png
  • $$ TsO-CH_2 - C \equiv CH$$
  • $$ TsO_2-CH_2 - C \equiv CH$$
  • $$ TsO-CH_2 - C - CH_3$$
  • none of the above
Which of the following is the correct method for synthesizing methyl-t-butyl ether?
  • $$\displaystyle \left ( CH_{3} \right )_{3}CBr+NaOMe\rightarrow $$
  • $$\displaystyle \left ( CH_{3} \right )_{3}CONa+MeBr\rightarrow $$
  • $$\displaystyle \left ( CH_{3} \right )_{3}CBr+HOMe\rightarrow $$
  • Both A and B
Which of the following are possible products in the above reaction?
137127_901b502cf66348ac801a42f9a1ef3bc9.png
Identify $$B$$ and $$C$$ respectively in following conversion.
137079_8382d85466c147da99201637294b98f3.png
  • None of the above
 In given reaction  A is :
146711_e37c675569a34f3280650c9470a92446.png
Which method is useful for the synthesis of ether?
Primary alcohols can be prepared from alkenes by:
  • mercuration and demercuration of alkenes
  • direct hydration of alkenes
  • hydroboration of alkenes
  • all of the above
Reactions I and II are limited mainly to naphthalene compounds. These reactions are called, respectively:
247470_620943915daa431c89d0e79affc2d8dd.png
  • bucherer reaction and its reversal
  • bischler-Napieralski reaction and its reversal
  • birnbaum-Simonini reaction and its reversal
  • borodine-Hunsdiecker reaction and its reversal
Which of the following statements is/are correct?
247363.bmp
  • The compounds (B) is (I).
  • The compounds (B) is (II)
  • The compounds (C) is (I)
  • The compounds (C) is (II)
The compound (A) is:
249321_3644845d0e0043c79481076ed30ec119.png
Which statement is correct for the conversion of $$ROH$$ to $$RX$$ by reagents $$(A)$$ $$ ( SOCl_{2},\ PBr_{3}$$ $$ PCl_{3}$$ $$ Pl_{3},\:TsCl  )$$ compared to using $$HX$$?
  • No rearrangement occurs with predictable stereochemistry by reagents $$(A)$$
  • Reasgents $$(A)$$ are not useful for $$\displaystyle 3^{\circ}$$ alcohols, while $$HX$$ reacts easily with $$\displaystyle 3^{\circ}$$ alcohols involving no rearrangement.
  • Reagents $$(A)$$ must be used in anhydrous conditions because all react vigorously with $$\displaystyle H_{2}O$$ and they produce harmful gases $$\displaystyle \left ( SO_{2},HCl,HBr,\:and\:HI \right )$$
  • All of the above
Which is the best method for the conversion of (A) $$pentan-3-ol\ to\ 3-bromopentane$$ (B)?

  • $$\displaystyle \left ( A \right )\xrightarrow {HBr}\left ( B \right )$$
  • None of these
Which of the following reaction is feasible for the preparation of 1-propoxy-2 methyl propane?
  • Williamson's synthesis of $$\displaystyle \left ( Me_{2}CHCH_{2}ONa+MeCH_{2}CH_{2}Cl \right )$$
  • Williamson's synthesis of $$\displaystyle \left ( Me_{2}CHCH_{2}Cl+MeCH_{2}CH_{2}ONa \right )$$
  • Alkoxymercuration-demercuration of $$\displaystyle \left ( Me_{2}C= CH_{2}+MeCH_{2}CH_{2}OH \right )$$
  • Alkoxy mercuration demercuration of propene with $$\displaystyle Me_{2}CHCH_{2}OH$$
Give the decreasing order of reactivity of the following compounds with $$HBr$$.

249648_2ead6a661a6041dbb0e7cd272bb4f9bd.png
  • III > IV > II > I
  • III > II > IV > I
  • III> II > I > IV
  • II > III > IV > I
Consider the following reaction sequence.
$$\displaystyle { CH }_{ 2 }={ CH }_{ 2 }\xrightarrow [ dil.{ KMnO }_{ 4 } ]{ cold } A\xrightarrow [ { PCl }_{ 5 } ]{ excess } B$$

The products $$(A)$$ and $$(B)$$ are, respectively:
  • $$\displaystyle { CH }_{ 3 }{ CH }_{ 2 }OH$$ and $$\displaystyle { CH }_{ 3 }{ CH }_{ 2 }Cl$$
  • $$\displaystyle { CH }_{ 3 }{ CHO }$$ and $$\displaystyle { CH }_{ 3 }{ CHCl }_{ 2 }$$
  • $$\displaystyle { CH }_{ 2 }OH { CH }_{ 2 }OH$$ and $$\displaystyle { CH }_{ 2 }Cl{ CH }_{ 2 }Cl$$
  • $$\displaystyle { CH }_{ 2 }OH{ CH }_{ 2 }OH$$ and $$\displaystyle { CH }_{ 2 }OH{ CH }_{ 2 }Cl$$

251495.png
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • Assertion is correct but Reason is incorrect
  • Both Assertion and Reason are incorrect
The product (B) is :

249658_01ff5e1ec5f04b53a5a9a3c7b38af82b.png
  • All
$$PhCH=C{ H }_{ 2 }\overset { ArC{ O }_{ 3 }H }{ \underset { C{ H }_{ 2 }{ Cl }_{ 2 } }{ \longrightarrow  }  } A\overset { 1.LiAl{ H }_{ 4 }\cdot { Et }_{ 2 }O }{ \underset { 2.{ H }_{ 2 }O }{ \longrightarrow  }  } B$$
The end product (B) is :
  • $$PhCH(OH)C{ H }_{ 3 }$$
  • $$PhC{ H }_{ 2 }C{ H }_{ 2 }COAr$$
  • $$PhC{ H }_{ 2 }C{ H }_{ 2 }OH$$
Which of the following will result in the formation of an ether?
  • $${ \left( C{ H }_{ 3 } \right) }_{ 3 }C\overset { - }{ O } \overset { + }{ Na } +C{ H }_{ 3 }C{ H }_{ 2 }Br\longrightarrow $$
  • $${ \left( C{ H }_{ 3 } \right) }_{ 3 }CBr+{ C }_{ 2 }{ H }_{ 5 }\overset { - }{ O } \overset { + }{ N } a\longrightarrow $$
  • $${ C }_{ 6 }{ H }_{ 5 }ONa+C{ H }_{ 3 }Br\longrightarrow $$
  • $${ C }_{ 6 }{ H }_{ 5 }Br+C{ H }_{ 3 }\overset { - }{ O } \overset { + }{ N } a\longrightarrow $$
Propene is allowed to react with m-chloroperoxybenzoic acid. The product (A) is then reduced with $$\displaystyle { LiAlH }_{ 4 }$$ in dry ether to give (B).

$$\displaystyle { CH }_{ 3 }CH={ CH }_{ 2 }\xrightarrow { m-CPBA }\    A\xrightarrow [ 2.{ H }_{ 3 }{ O }^{ + } ]{ 1.{ LiAlH }_{ 4 } } B$$

The structure of the product (B) is:
  • $$\displaystyle { CH }_{ 3 }{ CH(OH)CH }_{ 2 }OH$$
  • $$\displaystyle { CH }_{ 3 }{ CH }_{ 2 }{ CH }_{ 2 }OH$$
  • $$\displaystyle { CH }_{ 3 }{ CH }(OH)CH_{ 3 }$$
For the reaction given, what is product $$(A)$$?
253318_521e595ebd4148ba974f4ec440b7708a.png
Which statement is correct for the conversion of ROH to RX by reagents $$\displaystyle \left ( SOCl_{2},PBr_{3},PCl_{3},PI_{3} \right )$$  and TsCl compared to using HX?
  • No rearrangement occurs with predictable stereo-chemistry by reagents
  • Reagents are not useful for $$\displaystyle 3^{\circ}$$ alcohols, while HX reacts easily with $$\displaystyle 3^{\circ}$$ alcohols involving no rearrangement
  • Reagents must be used in anhydrous conditions because all react vigrously with $$\displaystyle H_{2}O$$ and they produce harmful gases ($$\displaystyle SO_{2}$$, HCl, HBr, and HI)
  • All
The product (B) is:

249652_99b8dffffd3140a3aa5294dccd4569db.png
  • all
Consider the reaction:

 $$\displaystyle C_{3}H_{7}-OH+Et{O^{\bigoplus }}BF_{4}^{\circleddash }\rightarrow C_{3}H_{7}-O-Et+EtOEt$$. 

Which of the following statements is wrong?
  • The nucleophile in the reaction is $$\displaystyle C_{3}H_{7}O^-$$
  • The nucleophile in the reaction is $$\displaystyle BF_{4}^{{\circleddash }}$$
  • The leaving group is $$\displaystyle Et_{2}O$$
  • $$\displaystyle SN^{2}$$ reaction occurs
A compound (X) reacts with thionyl chloride to give a compound (Y). (Y) reacts with $$\displaystyle Mg$$ to form a Grignard reagent, which is treated with acetone and the product is hydrolysed to give 2-methyl-2- butanol. What are structural formulae of (X) and (Y) ?
  • X = Acetic acid Y = Ethyl Chloride
  • X = Acetaldehyde Y = Ethyl Chloride
  • X = Ethyl Alcohol Y = Ethyl Chloride
  • X = Propyl alcohol Y = Propyl Chloride
Select the incorrect synthesis.
In which of the following solvents, KI has highest solubility? The dielectric constant $$(\epsilon)$$ of each liquid is given in parentheses.
  • $$ C_{6}H_{6}(\epsilon =0)$$
  • $$(CH_{3})_{2}CO(\epsilon =21)$$
  • $$CH_{3}OH(\epsilon =32)$$
  • $$CCl_{4}(\epsilon =0)$$
For the reaction the major product is:

274431.png
Complete the blanks by identifying $$X$$ and $$Y$$.
399096_eb04222c956244ec8a6cd2961faf5cba.png
  • Ethanal, ethene
  • Ethanol, ethene
  • Ethanal, ethyne
  • Ethanol, ethyne
The boiling point of phenols are higher than the hydrocarbons of comparable masses due to:
  • more polarising power
  • presence of hydrogen bonding
  • resonance stabilisation
  • acidic character
m-Methoxyphenol is a weaker acid than phenol.
  • True
  • False
Correct statement(s) in case of n-butanol and t-butanol is (are):
  • both are having equal solubility in water.
  • t-butanol is more soluble in water than n-butanol.
  • boiling point of t-butanol is lower than n-butanol.
  • boiling point of n-butanol is lower than t-butanol.
Which of the following has lowest boiling point?
  • $$p$$-nitrophenol
  • $$m$$-nitrophenol
  • $$o$$-nitrophenol
  • phenol
Identify the correct sequence of given steps for the conversion of calcium carbide to methyl alcohol.
(a) Reaction with aqueous $$KOH$$
(b) Hydrolysis
(c) Reaction with soda lime
(d) Reaction with $$Ha{SO}_{4}/{H}_{2}{SO}_{4}$$
(e) Reaction with $$Hg{SO}_{4}$$
(f) Reaction with $$P{Cl}_{5}$$
  • $$b\ d\ e\ c\ f\ a$$
  • $$b\ d\ c\ a\ f\ e$$
  • $$b\ f\ d\ e\ a\ c$$
  • $$d\ b\ c\ e\ f \ a$$
Ethanol is produced by/from :
  • ethene
  • fermentation of sugars
  • both A and B
  • none of the above
$$R-OH\xrightarrow{PBr_3}A\xrightarrow[]{Mg/Dry \ ether}B\xrightarrow[]{HCHO}C\xrightarrow[]{H^+/H_2O}D$$

What are $$A,B,C$$ & $$D$$ respectively?
  • $$R-Br,R-Br-Mg,R-CH_2Mg-Br,R-CH_2CHO$$
  • $$R-Br,R-Mg-Br,R-CH_2-O-Mg-Br,R-CH_2CHO$$
  • $$R-Br,R-Mg-Br,R-CH_2-O-Mg-Br,R-CH_2OH$$
  • $$R-Br,R-Mg-Br,R-CH_2-Br,R-CH_2OH$$
Which one of the following is produced when acetone is saturated with $$HCl$$ gas?
  • Acetone alcohol
  • Phorone
  • Mesityl oxide
  • Benzene
$$CH_3CH_2-OH\xrightarrow{A}CH_3-CH_2-Cl\xrightarrow{B}CH_2=CH_2.$$

 A and B in this sequence of reactions are :
  • KOH(aq) and $$PCl_5$$
  • $$PCl_5$$ and KOH(aq)
  • $$Cl_2$$ and KOH(alc)
  • $$PCl_5$$ and KOH(alc)
$$R-OH\xrightarrow {P+I_2}A\xrightarrow[alc. \ KCN]{Heating}B\xrightarrow[Na/alcohol]{LiAlH_4}C\xrightarrow[NaNO_2+dil\  HCl]{HNO_2}D$$

What are $$A,B,C$$ & $$D$$ respectively?
  • $$R-I$$, $$R-CN$$, $$R-NH_2$$, $$R-CH_2OH$$
  • $$R-I$$, $$R-CN$$, $$R-CH_2-NH_2$$, $$R-CH_2OH$$
  • $$R-I$$, $$R-NC$$, $$R-CH_2-NH_2$$, $$R-CH_2OH$$
  • $$R-I$$, $$R-CN$$, $$R-CH_2-NO_2$$, $$R-CH_2OH$$
$$R-OH\xrightarrow {PBr_3}A\xrightarrow[]{Mg/Dry \ ether}B\xrightarrow[CH_2-CH_2-O]{Grignard\ reaction}C\xrightarrow[]{H^+/H_2O}D$$

What are $$A,B,C$$ and $$D$$ are respectively?
  • $$R-Br,R-Mg-Br,R-CH_2-O-Mg-Br,R-CH_2CH_2-OH$$
  • $$R-Br,R-Mg-Br,R-CH_2-O-CH_2-Mg-Br,R-CH_2CH_2-OH$$
  • $$R-Br,R-Mg-Br,R-CH_2-CH_2-O-Mg-Br,R-CH_2CH_2-OH$$
  • $$R-Br,R-Mg-Br,R-CH_2-CH_2-O-Mg-Br,R-CH_2OH$$
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