Q: The reaction sequence given below is carried out with 16 moles of X . The yield of the major product in each step is given below the product in parentheses. The amount (in grams) of S produced is ____

aligned & M = ( C _6 H _4 )_2 ( C _6 H _5 )_2 C _2 H _4 O \\ & =350 aligned Weight of product of S=350 1 / 2=175 gm Ans. * WES : Williamson ether synthesis

Q: Match the reactions in List-I with the features of their products in List-II and choose the correct option. List I List II ( P ) - - 1 - Bromo - 2 - ethylpentane ( Single enantiom

1 - Bromo - 2 - ethylpentane ( Single enantiomer ) → S N 2 reaction aq . NaOH 2 - ethylpentanol In the above reaction the chiral carbon is not involving in the reaction as S N 2 reaction takes place via formation of transition state but not through formation of intermediate. In the above reaction, bromine attached to chiral carbon, and it is involving in S N 2 reaction. Hence, the alcohol formed in inversion configurat

Q: Paragraph: The amount of energy required to break a bond is same as the amount of energy released when the same bond is formed. In gaseous state, the energy required for homolytic cleavage of a bond i

CH 4 g + Cl 2 g → light CH 3 Cl g + HCl g ΔH r ∘ = ∑ BDE reactans − ∑ BDE products = E C − H + E Cl − Cl − E C − Cl − E H − Cl = + 105 + 58 − 85 − 103 = − 25 k cal mol − 1 reaction is exothermic.

Question 1

For the reaction sequence given below, the correct statement(s) is(are) (In the options, X is any atom other than carbon and hydrogen, and it is different in P , Q and R )

Accepted Answer

(A) Wrong: bond length order Q > P > R (B) Correct: Bond enthalpy R > P > Q (C) Wrong: S _ N 2 reactivity Q > P > R (D) Wrong: pKa ( HI P > Q ( pKa )

Question 2

The reaction sequence given below is carried out with 16 moles of X . The yield of the major product in each step is given below the product in parentheses. The amount (in grams) of S produced is ____

Accepted Answer

aligned & M = ( C _6 H _4 )_2 ( C _6 H _5 )_2 C _2 H _4 O \ & =350 aligned Weight of product of S=350 1 / 2=175 gm Ans. * WES : Williamson ether synthesis

Question 3

The reaction of 4 -methyloct- 1 -ene ( P , 2 . 52 &#160; g ) with HBr in the presence of C 6 H 5 CO 2 O 2  gives two isomeric bromides in a 9 : &#160; 1  ratio, with a combined yield of 50 %

Accepted Answer

The 1-alkene undergo addition reaction and major product formed according to anti-Markonikov's rule. Moles of  P   = Mass &#160; of &#160; P Molar &#160; mass &#160; of &#160; P = 2 . 52 252 = 0 . 01 &#160; mol Given that isomeric bromides formed have the mole fractions  9 10  and  1 10 Moles of  A (major product)  = 0 . 02 &#215; 9 10 &#215; 50 100 = 0 . 009 &#160; mol Now the alkyl bromide formed undergo nucleophilic substitution reaction with d

Question 4

Match the reactions in List-I with the features of their products in List-II and choose the correct option.   List I   List II ( P ) - - 1 - Bromo - 2 - ethylpentane ( Single &#160; enantiom

Accepted Answer

1 - Bromo - 2 - ethylpentane ( Single &#160; enantiomer ) &#160; &#160; &#8594; S N &#160; 2 &#160; &#160; reaction aq .&#160; NaOH 2 - ethylpentanol In the above reaction the chiral carbon is not involving in the reaction as  S N 2  reaction takes place via formation of transition state but not through formation of intermediate. In the above reaction, bromine attached to chiral carbon, and it is involving in  S N 2  reaction. Hence, the alcohol formed in inversion configurat

Question 5

Considering the following reaction sequence, the correct statement(s) is(are)

Accepted Answer

Benzene undergoes friedel craft's reaction with succinic anhydride in presence of anhydrous AlCl 3  to form P.The mechanism of the reaction is electrophilic substitution. The keto group in P gets reduced on reaction Zn/Hg in HCl to form Q that is 4-phenylbutanoic acid. This reacts with thionyl chloride to form R, that is  4-Phenylbutanoyl chloride. R again undergoes friedel craft's reaction to form S. S gets reduced on reaction Zn/Hg in HCl to form a hydrocarbon

Question 6

Paragraph: The amount of energy required to break a bond is same as the amount of energy released when the same bond is formed. In gaseous state, the energy required for homolytic cleavage of a bond i

Accepted Answer

CH 4 g + Cl 2 g &#8594; light CH 3 Cl g + HCl g &#916;H r &#8728; = &#8721; BDE reactans &#8722; &#8721; BDE products = E C &#8722; H + E Cl &#8722; Cl &#8722; E C &#8722; Cl &#8722; E H &#8722; Cl = + 105 + 58 &#8722; 85 &#8722; 103 = &#8722; 25 &#160; k &#160; cal &#160; mol &#8722; 1 reaction is exothermic.

Question 7

The maximum number of possible isomers (including stereoisomers) which may be formed on mono -bromination of 1 -methylcyclohex-  1 -ene using Br 2 and UV  light is ___.

Accepted Answer

Allylic position is the most reactive centre First free radical will give following products 2 nd  free radical can give following products 3 rd  free radical can give following products

Question 8

Choose the correct option(s) for the following reaction sequence Consider Q , R and S as major products.

Accepted Answer

Answer option index: 3

Question 9

Choose the correct option(s) for the following set of reactions

Accepted Answer

Answer option index: 3

Haloalkanes and Haloarenes — Previous Year Questions & Solutions