Q: Consider the following reaction. On estimation of bromine in 1 . 00 g of R using Carius method, the amount of AgBr formed (in g ) is____[Given: Atomic mass of H = 1 , C = 12 , &#16

2 P + 3 Br 2 → 2 PBr 3 Number of moles in 1 gm of R = 1 250 using Carius method all the Br will be converted into AgBr. So, using POAC method Number of moles of AgBr formed from R = 2 250 Mass of AgBr formed = 2 × 188 250 = 1 . 50 gm

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

Relative stability of radicals : C ∙ sp ≡ CH > C ∙ H sp 2 = CH 2 > C ∙ H 2 − Ph sp 3 Resonance stabilized > C ∙ H CH 3 2 sp 3 So, BDE H − C ≡ CH H − CH = CH 2 H − CH 2 − Ph H − CH CH 3 2 BDE 132 110 88 95 Electronegativity ∝ % s - character ∝ bon

Q: The reaction of Q with PhSNa yields an organic compound (major product) that gives positive Carius test on treatment with Na 2 O 2 followed by addition of BaCl 2 . The correct option s fo

Q → PhSNa major organic compound Hence, it is confirmed that ' Q ' gives S N 2 reaction or ArS N type reaction. The product of the bove reaction give positive Carius tube test. The product of the bove reaction give positive Carius tube test.

Question 1

Consider the depicted hydrogen ( H ) in the hydrocarbons given below. The most acidic hydrogen ( H ) is

Accepted Answer

B is most acidic : It forms most stable conjugate base.

Question 2

The monomer (X) involved in the synthesis of Nylon 6,6 gives positive carbylamine test. If 10 moles of X are analyzed using Dumas method, the amount (in grams) of nitrogen gas evolved is ______ . Use:

Accepted Answer

Hexamethylene diamine series give (+) carbylamine test. C _ x H _ y N _ z +(2 x +1 / 2) CuO xCO _2+ y 2 H _2 O + z 2 ~N _2 (Dumas method) C _6 H _ 16 ~N _2 then z 2 ~N _2= 2 2 ~N _2=1 mole Given 10 mole in this reaction so w _ N _2 =10 28=280 gm

Question 3

The total number of chiral molecules formed from one molecule of P on complete ozonolysis O 3 , Zn / H 2 O is _____

Accepted Answer

The Ozonolysis mechanism proceeds via an oxidative cleavage reaction. The ozone not only breaks the carbon pi bond but also the carbon-carbon sigma bond. It involves the attack of ozone on the given reactant to form an ozonide. To eliminate the oxygen in this intermediate stage, zinc dust is employed (since it forms zinc oxide with oxygen). In reductive ozonolysis the ozonide is treated with mild reducing agents such as dimethyl sulfide and zinc metal with water. The ozonide is reduced as s

Question 4

Consider the following reaction. On estimation of bromine in 1 . 00 &#160; g of  R using Carius method, the amount of AgBr formed (in g ) is____[Given: Atomic mass of H = 1 , &#160; C = 12 , &#16

Accepted Answer

2 P + 3 Br 2 &#8594; 2 PBr 3 Number of moles in 1 gm of  R = 1 250 using Carius method all the Br will be converted into AgBr. So, using POAC method Number of moles of AgBr formed from  R = 2 250 Mass of AgBr formed  = 2 &#215; 188 250 = 1 . 50 gm

Question 5

If the reaction sequence given below is carried out with 15  moles of acetylene, the amount of the product D  formed (in g ) is The yields of  A , B , C and D are given in parentheses.

Accepted Answer

Molecular formula of D is  C 8 H 8 O 2 Molar mass of D  is  12 &#215; 8 + 8 &#215; 1 + 16 &#215; 2 = 136 &#160; g &#8756; Mass of D  is  136

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

Relative stability of radicals : C &#8729; sp &#8801; CH &#62; C &#8729; H sp 2 = CH 2 &#62; C &#8729; H 2 &#8722; Ph sp 3 &#160; Resonance &#160; stabilized &#62; C &#8729; H CH 3 2 sp 3 So,  BDE   H &#8722; C &#8801; CH H &#8722; CH = CH 2 H &#8722; CH 2 &#8722; Ph H &#8722; CH CH 3 2 BDE 132 110 88 95 Electronegativity  &#8733; &#160; % &#160; s - character                               &#8733;  bon

Question 7

Among the following, the conformation that corresponds to the most stable conformation of meso -butane- 2 , 3 -diol is

Accepted Answer

meso -butane- 2 , 3 -diol is The Gauche form will be the most stable due to the presence of an intramolecular  H -bonding between both hydroxy group.

Question 8

The reaction of Q with PhSNa yields an organic compound (major product) that gives positive Carius test on treatment with &#160; Na 2 O 2 followed by addition of BaCl 2 . The correct option s  fo

Accepted Answer

Q &#8594; PhSNa major &#160; organic &#160; compound Hence, it is confirmed that ' Q ' gives  S N 2  reaction or  ArS N  type reaction. The product of the bove reaction give positive Carius tube test. The product of the bove reaction give positive Carius tube test.

Question 9

An organic compound C 8 H 10 O 2 rotates plane-polarized light. It produces pink color with neutral FeCl 3  solution. What is the total number of all the possible isomers for this compound?

Accepted Answer

Since compound C 8 H 10 O 2 corresponds positively to neutral FeCl 3 hence it will be a phenolic compound the possible structures which are optically active are as followed Hence, total optically active isomers will be 6 .

Question 10

Consider the following transformations of a compound P . Choose the correct option(s).

Accepted Answer

Answer option index: 2

Question 11

Newman projections P , Q , R and S are shown below: Which one of the following options represent identical molecules?

Accepted Answer

Answer option index: 2

Question 12

Which one of the following structures has the IUPAC name 3 -ethynyl- 2 -hydroxy- 4 -methylhex- 3 -en- 5 -ynoic acid?

Accepted Answer

3 -ethynyl- 2 -hydroxy- 4 -methylhex- 3 -en- 5 -ynoic acid

Question 13

The Fischer projection of D -erythrose is shown below. D -Erythrose and its isomers are listed as P , Q , R , and S in Column I. Choose the correct relationship of P , Q , R , and S with D -erythrose

Accepted Answer

Answer option index: 2

Question 14

With respect to the compounds I - V choose the correct statement(s).

Accepted Answer

( A ) is stabilised by conjugation ( B ) Conjugation base of is which is an aromatic anion ( C ) - NO 2 group is an electron withdrawing group it increases acidic strength of any compound to which it is added. ( D ) The acidic strength order on the basis of pK a data IV > V > I > II > III is

Question 15

In the following reaction, compound Q is obtained from compound P via an ionic intermediate. What is the degree of unsaturation of Q ?

Accepted Answer

Answer option index: 0

Question 16

Choose the correct option(s) that give(s) an aromatic compound as the major product.

Accepted Answer

A B C D

Question 17

Total number of isomers, considering both structural and stereoisomers, of cyclic ethers with the molecular formula C 4 H 8 O is ________

Accepted Answer

Total number of isomers considering both structural and stereoisomers, of cyclic ether with molecular formula = 10

General Organic Chemistry — Previous Year Questions & Solutions