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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
Assettio (A) : `Ph overset (o+) (N_2) Br^(Θ)` on reaction with `NaOH` gives bebzene diazohroxile Reason (R ) : `overset (Θ) (OH)` is a strong nucleophile , attacks the terminal (N) atom , and forms a covalent bond.A. If both (A) and (R ) ar true, and (R ) is the correct explanation of (A).B. If both (A) and (R ) are true , and (R ) is not the correct explanation of (A).C. If (A) is true , but (R ) is false .D. If both (A) and (R ) are false . |
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Answer» Correct Answer - A Both (A) and (R ) are true and (R ) is the correct explanation of (A). . |
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| 102. |
Assertion (A) : Hofmann bromamide reaction takes place btween an arthide and `Br_2` in basic medium . ltbRgt Reason (R ). The reaction proceeds by the formation of `(R-overlineN: )` nitrene intremediate.A. If both (A) and (R ) ar true, and (R ) is the correct explanation of (A).B. If both (A) and (R ) are true , and (R ) is not the correct explanation of (A).C. If (A) is true , but (R ) is false .D. If both (A) and (R ) are false . |
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Answer» Correct Answer - C The intermediate is acyl nitrene ` R-overset(O)overset(||)(C )-ddot(N:)`. |
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| 103. |
Statement 1: The product formed is (B). Statement 2: The reaction proceeds via the formation of the following species in the order: Radical anion `rarr` Vinylic anion `rarr` Vinylic redical `rarr` ProductA. a.Statement 1 and Statement 2 are true and Statement 2 is the correct explanation of Statement 1.B. b.Statement 1 and Statement 2 are true and Statement 2 is not the correct explanation of Statement 1.C. c.Statement 1 is true and statement 2 is false.D. d.Statement 1 is false and statement 2 is false |
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Answer» Correct Answer - C The reduction of `(C-=C)` to `(C=C)` takes place by anti-addition of hydrogen with `(Na+ liq. NH_(3) + EtOH)`, so the product formed is `(B)`. Statement `1` is true. But statement `2` is false, since the mechanism of the reaction proceeds as follows. Radical anion `rarr` Vinylic redical `rarr` Vinylic anion rarr product. Statement `1` is true and statement `2` is false. So the answer is `(c )`. |
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| 104. |
` CHl_3 overset (HNO_3) (rarr) (X)` ltbRgt In the above sequence , (X ) is :A. NitrochloromethaneB. ChloropicrinC. EthanenitrileD. None of the above |
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Answer» Correct Answer - B ` H-C.Cl_3 overset (HNO_3) (rarr) underset ("Chloropicrin") (O_2-C Cl_3)`. |
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| 105. |
Which of the following is formed when ` RNH_2` reacts with ` RCHO`?A. HemiacetalsB. AcetalsC. KetalsD. Imines |
| Answer» Correct Answer - D | |
| 106. |
Primary and secondary amines are distinguished by :A. `Br_2//KOH`B. `HClO`C. `NHO_2`D. `NH_3` |
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Answer» Correct Answer - C ` HNO_2` is used to distinguish between ` 1^@, 2^@`, and ` 3^@` amines . |
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| 107. |
The conjugate base of ` (CH_3) NH_2^(o+)` is :A. `(CH_3)_3N`B. `(CH_3)_2NH`C. `(CH_3CH_2)_2NH_2`D. `C_6H_5NHCH_2` |
| Answer» Correct Answer - B | |
| 108. |
Which of the following reactions does not yield an amine?A. ` R-X + NH_3 rarr`B. ` R -CH = NOH = [H] overset(Na)underset(C_(2)H_(5)OH)rarr`C. `R-CN+H_2O overset (H^(o+))rarr`D. `R-CONH+ 4 [H] overset(LiAIH_(4))rarr` |
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Answer» Correct Answer - C `RCN` on hydrolysis disinguish between ` 1^@. 2^@` and `3^@` amines . |
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| 109. |
A gas is found to have the formula `(CO)_n` if its vapour density is 56 the value of n will beA. 7B. 5C. 4D. 3 |
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Answer» Correct Answer - C V.D.=56 Mol.mass =2xxV.D=2xx56=112 `(CO)_(n)=112 "or" (12+16)_(n)=112 ` `(28)_(n)=112 "or"n=(112)/(28)=4` |
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| 110. |
Which of the following statement are correct reactions?A. B. C. D. |
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Answer» Correct Answer - A::B::C (d) is incorrect , since Gabriel method is used to prepare `1^@` aliphatic amines . a. Reductive amination gives beter yield b. Although `2^@` alkyl bromide , elimaination fo ` HBr` may take place , bowever it can be prepared by this method . Azode ,method is also feasible since `N_3^Θ` is a good bucleophile. |
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| 111. |
Which statements(s) is//are correct: A. a.The intermediates I and II can be isolated.B. b.In the intermediates I and II, all the resonance energy has been lost and the activation anergy of this step is much greater than that required for each succeeding step in which the double bond behave like their acylic analogue.C. c.The conditions required for the formation of I and II are more vigorous than those required for the successive steps.D. d.Because to this, it is not possible to stop the reaction proceeding to complete the reduction of benzene to II (cyclohexane), and consequently it is not possible ti isolate the intermediates II and III. |
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Answer» Correct Answer - B::C::D All the statements are explanations in themselves. |
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| 112. |
How do you distinguish the Propanal and propanone pairs of compound . |
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Answer» Propanel and propanone On idoform test propanone responds, but absence of `CH_(3)CO`-group in propanal `(CH_(3)CH_(2)CHO)` it does not respond. `underset("Propanone")(CH_(3)CO CH_(3))+underset("Sodium hypoiodite")(3NaOI) underset("Heat")overset(NaOH, I_(2))to underset("(Yellow ppt. idoform)")(CHI_(3)darr) + underset("Sodium acetate")(CH_(3)COONa)+2NaOH` |
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| 113. |
How do you distinguish the Pentan-2-one and pentan-3-one pairs of compound . |
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Answer» Pentan-2-one and Pentan-3-one On idoform test Pentan-3-One responds whereas Pentan-3-one `(C_(2)H_(5)COC_(2)H_(5))` does not `underset("Pentan-2-one")(overset(1)CH_(3)-overset(2)CO-overset(3)CH_(2)-overset(4)CH_(2)-overset(5)CH_(3))+3NaOI underset("Heat")overset(NaOH , I_(3))to underset("Yellow ppt.")(CHI_(3)uarr + CH_(3)CH_(2)CH_(2)COONa+2NaOH)` |
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| 114. |
The compounds `(A)` and `(B)` are:A. a.`No reaction`B. b.C. c.D. d. |
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Answer» Correct Answer - D In `(A), MnO_(2)` does not react with `1^(@)` or `2^(@)` alcohols. It oxidises only allylic or benzylic alcoholic group. In `(B), PC C` oxidies `1^(@) ROH` to aldehyde without affecting the `(C=C)` bond. So the answer is `(d)`. |
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| 115. |
The compound (A)A. a.B. b.C. c.D. d.`No reaction` |
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Answer» Correct Answer - D `3^(@) (RNO_(2))` group does not react with `HNO_(2) (NaNO_(2)+HCl rarrHNO_(2)+NaCl)`, since it does not contain `alpha-H` atoms. So the answer is `(d)`. |
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| 116. |
Of the following compounds, whose ozonolysis proves the Kekule structure of benzene?A. a.BenzeneB. b.TolueneC. c.o-XyleneD. d.p-Xylene |
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Answer» Correct Answer - C o-Xylene on ozonolysis gives glyoxal: methylglyoxal: dimethyl glyoxal in the ratio `3:2:1`, which proves the existance of resonance in benzene and hence proves the Kekule structure of benzene. So the answer is `(c )`. |
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| 117. |
Mendius reaction involves the:A. Reduction of aldehydes to give alcoholsB. Reduction of nitriles with sodium and ethanolC. Oxidation of nitrilesD. Hydrolysis of cyanides. |
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Answer» Correct Answer - B `R-C-=Nunderset(Na+EtOH)overset("mendius reduction")toRCH_2NH_2` |
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| 118. |
Which of the following is not an ambident nucleophile?A. `NO_2^(ɵ)`B. `overset(ɵ)(O)H`C. `CSN^(ɵ)`D. `CN^(ɵ)` |
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Answer» Correct Answer - B (b) is not an ambident nucleophile, but other are. (a) a. `O=overset(..)underset(uarr)N-ddotunderset(uarr)underset(..)O:^(Theta)` c. `:overset(Theta)underset(uarr)N=C=ddotunderset(uarr)S:` d. `overset(Theta)underset(uarr)C=overset(..)underset(uarr)N` `(uarr)` indicates nucleophilic centres. |
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| 119. |
Which of the following groups will facilitate the electrophilic attackon benzene ring?A. `-NO_2`B. `-CHO`C. `-Cl`D. `-SO_3H` |
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Answer» Correct Answer - C SE reaction is favoured by EDG. `(-NO_2),(-CHO)` and `(-SO_3H)` are EWG. Cl is `overline(e)` donating by `(+R)` effect and deactivating by `(-I)`. |
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| 120. |
Which of the following statements is correct?A. Methyl amine is slighty acidic.B. Methyl amine is less basic than ammonia.C. Methyl amine is less basic than dimethyl amine.D. Methyl amine is less basic than aniline. |
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Answer» Correct Answer - C Dimethyl amine `(Me_2NH)` is more basic than `MeNH_2` due to `(+I)` effect two `(Me)` groups. |
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| 121. |
Arrange the following in the decreasing order of their basic strength : a. i. `PhNH_2` ii.` EtNH_2 ` ii. `EtNH_2` iii. `Et_2NH` iv, `NH_3` b. i. ` EtNH _2 ` ii. ` PhNH_2` iii . `NH_3 ` iv. `PhCH_2 NH_2` v.`Et_(2)NH` c. i. `EtNH_2` ii. `Et_2` ii. `Et_3N ` iv `PhCH_2NH_2` d. i. ` MeNH_2` ii. ` Me_2NH` ii.` Me_3N ` iv. `PhNH_2` v. ` PhCH_2NH_2` II. Complete the following acid -base reaction and name the products . i. |
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Answer» I. a. Aliphatic `2^@` amine gt Aliphatic `1^@` amine gt ` NH_3` gt Aromatic amine `(iii) gt (ii) gt (i)` b. `(v) gt (i) gt (iv) gt (iii) gt (ii)` c. ` (ii) gt (iii) gt (i) gt (iv)` d. ` (ii) gt (i) gt (iii) gt (v) gt (iv)` II . ii. `Et_3 N^(o+) Cl^(Θ)` (Propanammonium chloride ) |
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| 122. |
Absolute alcohol can be prepared from rectified spirit byA. distillation under reduced pressureB. azeotropic distillation with benzeneC. Fractional distillationD. Keeping over fresh CaO for few hours followed by distilling . |
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Answer» Correct Answer - B::D Absolute alcohol is manufactured from rectified spirit by azeotropic distillation with benzene.On a small scale, in laboratory, absolute alcohol can be prepared by keeping rectified spirit over fresh CaO (which absorbs water) for few hours followed by distillation |
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| 123. |
The weight of carbon ,hydrogen and oxygen in an organic compound are in the ratio 6 : 1 : 8 respectively .The molecular formula of compound may beA. `CH_2O`B. `C_3H_6O_3`C. `CH_2O_2`D. `C_2H_4O_4` |
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Answer» Correct Answer - A::B The ratio of weights `{:(C ,:,H,:,O) , (6 , : ,1,:,8):}` The atomic ratio `C : H : O` `(6)/(12) , (1)/(1) , (8)/(16) (("weight")/("At. Weight"))` Or `(1)/(2) : 1 : (1)/(2)` `1 : 2 : 1` `therefore` Empirical formula = `CH_(2)O` `therefore` Possible molecular formulae are `CH_(2)O(A)` and `C_(3)H_(6)O_(3) (B)` |
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| 124. |
Gabriel synthesis is used for the preparation ofA. `1^@` amineB. `2^@` amineC. `3^@` amineD. all can be prepared |
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Answer» Correct Answer - A `1^@` amine or `1^@` aromatic amine containing `EWG` at o- and p-positions. |
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| 125. |
The empirical formula of a compound is `CH_2` . To which of the following series can it belong ?A. AlkenesB. AlkynesC. AlkaneD. Cycloalkanes |
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Answer» Correct Answer - A::D General molecular formula of alkenes and cycloalkanes is the same i.e., `C_(n)H_(2n)`. As such they also have same empirical formula `CH_(2)`. |
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| 126. |
In a hydrocarbon, mass ratio of hydrogen and carbon is 1 : 3, the empirical formula of, hydrocarbon isA. CHB. `CH_(2)`C. `C_(2)H`D. `CH_(4)` |
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Answer» Correct Answer - D Mass of H:=1,At.mass of C=12 ,br. Mole of H:Moles of C `=1/1:3/12=1:1/4` `therefore E.F.=CH_4` ` therefore " Empirical formula is " CH_4` |
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| 127. |
Write chemical reactions of affect the Butan-1-ol to butanoic acid transformations. |
| Answer» `{:(CH_(3)CH_(2)CH_(2)CH_(2)OH underset("Jones reagent")overset(CrO_(3)-H_(2)SO_(4))to CH_(3)CH_(2)CH_(2)COOH),("Butan-1-ol"" ""Butanoic acid"):}` | |
| 128. |
The product `(A), is:A. a.B. b.C. c.D. d. |
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Answer» Correct Answer - C `LAH` reduces `ArNO_(2)` to `(Ar-N=N-Ar)` but does not reduce `ArX` (converts only `1^(@)` and `2^(@) RX` to `RH` and `3^(@) RX` to alkene). So the answer is `(c )`. |
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| 129. |
The product `(A), is:A. a.B. b.C. c.D. d. |
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Answer» Correct Answer - D `LAH` reduces `ArNO_(2)` to `(Ar-N=N-Ar)` but does not reduce `ArX` (converts only `1^(@)` and `2^(@) RX` to `RH` and `3^(@) RX` to alkene). So the answer is `(c )`. |
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| 130. |
The product `(A), is:A. a.B. b.C. c.D. d. |
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Answer» Correct Answer - A Birch reduction reduces one double bond of the benzene ring and gives a product with isolated double bond in which the `EDG` (e.g., here `(-CH_(3))` group) ends up on a double bond. So the answer is `(a)`. |
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| 131. |
The product `(A), is:A. a.B. b.C. c.D. d. |
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Answer» Correct Answer - A Same explanation as in answer to Q. No. (33) (iii). |
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| 132. |
The product `(A), is:A. No reactionB. b.C. c.D. d. |
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Answer» Correct Answer - A The isolated double bonds are not reduced by Birch reduction. So the answer is `(a)`. |
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| 133. |
The product `(A)`, and `(B)` are:A. a.B. b.C. c.D. d. |
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Answer» Correct Answer - D The phenols are not reduced by Birch reduction, whereas `ArX` gives the product containing isolated double bond without halogens. So the answer is `(d)`. |
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| 134. |
Predict the major product of acid catalysed dehydration of 1-methycyclohezanol |
| Answer» Correct Answer - 1-Methylcyclohexene | |
| 135. |
What is Dehydration ? Give equation. |
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Answer» Dehydration : Alcohols undergo dehydration in the presence of dehydrating agents like conc `H_(2)SO_(4),` (or) `H_(3)PO_(4)` etc and form alkenes . The relative ease of dehydration of alcohols follows the following order. Tertiary alcohol `gt` Secondary alcohol `gt` primary alcohol. `underset(""1^(@) "alcohol")(C_(2)H_(5)OH) underset(443)overset("Conc " H_(2)SO_(4))to CH_(2)=underset("ethene")(Ch_(2))+H_(2)O` `CH_(3)-underset(2^(@) "alcohol")underset(OH)underset(|)("CH")-CH_(3)underset(440K)overset(85%H_(3)PO_(3))to CH_(3)-underset("Propene")(CH=CH_(2))+H_(2)O` |
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| 136. |
What is Cannizaro reaction ? Give equation . |
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Answer» Cannizaro reaction : Aldehydes having no `alpha`-hydrogen undergo self oxidation and self reduction reaction on heating with alkali . In this reaction alcohol and salt of carboxylic acid are formed. `underset("formaldehyde")(2H-CHO) underset(Delta)overset(NaOH)to underset("Methanol")(CH_(3))+ OH + underset("Sodium formate")(NCOONa)` `underset("Benzaldehyde")(2C_(6)H_(5))-CHO overset(NaOH)to underset("Benzyl alcohol")(C_(6)H_(5)-underset(OH)underset(|)CH_(2)+ underset("Sodium benzate")(C_(6)H_(5)COONa))` |
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| 137. |
Vapour density of a volatile substance is ` 4 (O_(2)= 1). ` Its molecular weight would be A. 8B. 2C. 64D. 128 |
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Answer» Correct Answer - D If the vapour density of `O_(2)` is taken as 1 , then V.D of the O.C . = 4 . As the actual V.D of `O_(2) = 32//2 = 16` `therefore` Actual V.D of O.C = `16 xx 4 = 64`. Hence molecular mass of O.C = `2 xx 64 = 128` |
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| 138. |
Write any one method for the preparation of ethyl alcohol. |
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Answer» From Alkenes: Alcohols can be prepared from alkenes by hydration or hydroboration oxidation. i) `CH_(2)=CH_(2)+H_(2)O overset(+H)to CH_(3)-underset(OH)underset(|)(CH_(2))` |
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| 139. |
Which acid of each pair shown here would you expect to be stronger? `CH_(2)FCH_(2)CH_(2)CO_(2)H ` or `CH_(3)CHFCH_(2)CH_(2)CO_(2)H` |
| Answer» `CH_(3)CHFCH_(2)COOH` | |
| 140. |
Which acid of each pair shown here would you expect to be stronger? `CH_(2)FCO_(2)H ` or `CH_(2)ClCO_(2)H` |
| Answer» Correct Answer - `CH_(2)FCOOH` | |
| 141. |
Which acid of each pair shown here would you expect to be stronger? `CH_(3)CO_(2)H `or `CH_(2)FCO_(2)H` |
| Answer» Correct Answer - `CH_(3)COOH` | |
| 142. |
The yield of ketone when a secondary alcohol is oxidised is more than the yield of aldehyde when a primary alcohol is oxidised. |
| Answer» Since aldehydes are very susceptible to giving acids by further oxidation of `1^(@) ROH` but ketones are not easily oxidised, thus the yield of ketone is high. | |
| 143. |
Write the IUPAC names of the PhCOPh ketones and Aldehydes. Wherever possible , give also common names. |
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Answer» PhCOPh `C_(6)H_(5)-overset(O)overset(||)C-C_(6)H_(5)` IUPAC Name : Diphenyl methanone Common Name : Benzophenone |
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| 144. |
Write the IUPAC names of the `CH_(3)CH_(2)CHBrCH_(2)CH(CH_(3))CHO` ketones and Aldehydes. Wherever possible , give also common names. |
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Answer» `CH_(3)CH_(2)CHBrCH_(2)CH(CH_(3))CHO` `{:(6" "5" "4" "3" "2" " 1),(CH_(3)-CH_(2)-underset(Br)underset(|)CH-CH_(2)-underset(CH_(3))underset(|)(CH)-CHO):}` IUPAC Name : 4-bromo-2-methyl hexanal Common Name : `gamma`-bromo-`alpha`-methyl caproaldehyde |
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| 145. |
Chromic anhydride in `H_(2)SO_(4)` is not blue by:A. a.`1^(@)` alcoholB. b.`2^(@)` alcoholC. c.`3^(@)` alcoholD. d. |
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Answer» Correct Answer - C Since `3^(@)` alcohols are not oxidised by `("chromic anhydride" + H_(2)SO_(4))` or `(Cr_(2)O_(7)^(2-)+ H_(2)SO_(4))`, so no change of `Cr^(6+)` to `Cr^(3+)`. Hence, no change of colour. |
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| 146. |
Which is useful for separating benzoic acid from ethyl benzoateA. dil. HCl B. aq. `NaHCO_(3)`C. dil`H_(2)SO_(4)`D. dil.` HNO_(3)` |
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Answer» Correct Answer - B `C_(6)H_(5)COOH + NaHCO_(3) to C_(6)H_(5)COONa ("aq") + CO_(2) + H_(2)O` `underset(("Insoluble in water"))(C_(6)H_(5)COOC_(2)H_(5)) + NaHCO_(3) to "No action "` |
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| 147. |
The product `(A)` and `(B)` are:A. a.B. b.C. c.D. None |
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Answer» Correct Answer - A Lemieux reagent `KMnO_(4)//NaIO_(4)` oxidies `RCH !=` to `RCOOH` and `R_(2)C=` to `R_(2)C=O)`. So the answer is `(a)`. |
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| 148. |
How do you prepare the Acetic anhydride compound from acetic acid ? |
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Answer» Acetic anhydride : Carboxylic acids on heating in the presence of dehydrating agents like conc. `H_(2)SO_(4), P_(2)O_(5)` give anhydride. `CH_(3)-underset(O)underset(||)C-OH+HO -underset(O)underset(||)C-CH_(3) overset(P_(2)O_(5)//Delta)to CH_(3)-underset(O)underset(|)C-underset(O)underset(|)O-C-CH_(3)+H_(2)O` |
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| 149. |
How do you prepare the Acetamide compound from acetic acid ? |
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Answer» Acetamide formation (Reaction with ammonia) : Carboxylic acids reacts with Ammonia and form ammonium salt which on heating gives amides. `CH_(3)-COOH + NH_(3)O hArr underset("Ammonium acetate")(CH_(3) - Co overset(-)On overset(+)(H_(4)) underset(-H_(2)O) overset(Delta)to H_(3)C-underset(O)underset(||)C-NH_(2)` acetamide |
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| 150. |
How do you prepare the Acetyl chloride compound from acetic acid ? |
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Answer» Acetyl chloride : Raction with `PCl_(3) ` (or) `PCl_(5)` (or) `SOCl_(2)` : Carboxylic acids form acid chlorides with `PCl_(3), PCl_(5), SOCl_(2).` `CH_(3)COOH + PCl_(2) to CH_(3)COCl + POCl_(3) + HCl` `3CH_(3)COOH + PCl_(3) to 3CH_(3)COCl + 3H_(3)PO_(3)` `CH_(3)COOH + SOCl_(2) overset("Pyridine")to underset("Acetyl Chloride")(CH_(3)COCl + SO_(2)+HCl)` |
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