NET/JRF Important Previous year question and Solution

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Previous paper questions Solution discussion:-

1. Find the correct order of energy for the following molecular orbital is. 

1. 2 Anti molecular orbital,  0 Bonding molecular orbital 

2. 0 Anti molecular orbital, 2 Bonding molecular orbital 

3. 1 Anti molecular orbital,  2 Bonding molecular orbital 

A) 1>2>3

B) 1>3>2

C) 2>3>1

D) 2>1>3

Ans. B

Discussion:-

                    We know that anti molecular orbital energy is greater than Bonding molecular orbital so option B is right answer. 

2. Find the Stereo of given equation in the present of heat . 

  2E, 4Z, 6E Octatriene ------------------>  ?

A) cis

B) Trans

C) Both of above 

D) None of These 

Ans. A

We know that  Octatriene is ( 4n+2 ) system. 

      (4n+2) system show dis rotation in the present of heat. 

Trick:-    O             D                 C

        Opposite     dis               cis

Note :- one key is same or all key is same .

3. Find the Stereo of given equation in the present of heat. 

2E, 4Z, 6Z Octatriene ----------------------->  ?

A) cis

B) Trans 

C) both 

D) None of These 

Ans. B 

We know that Octatriene is (4n+2) system. 

      (4n+2) system show dis rotation in the present of heat. 

Trick:-     O                   D                     C

           Same                dis                 Trans 

Note :- one key is same or all key is same .

   

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1. Organic reactions|Introduction of Nucleophile and Electrophile

Important Maths Formula For Class-9

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Linear equations Formula:-

1. (A+B)²= A²+B²+2AB

2. (A-B)²=A²+ B ²-2AB

3. (A² -B ² )= (A+B)(A-B)

4. (A² +B ² )= (A+B)²-2AB

5. (A² +B ² )= (A+B)²+2AB

Mensuration Formula:-

1. Circle 

2. Triangle 

3. Calendar 

4. Rectangle 

5. Mix 

Time and distance Trick questions 

Join Maths Test Class-9 

1. Circle:-

A) area = /\r²        Where   r= radius of circle 

B) Parameter = 2/\r

2. Triangle:-

A) area = 1/2 base * hight 

3. Calendar:-

A) area = /\r²h       where r = radius of calendar 

                                           h = height of calendar 

B) Parameter = 2/\rh

4. Rectangle:-

A) area = l × b     where l = length and

                                           b = base

Parameter = 2 ( l + b) 

5. Mix :- 

               Find the area in Hero Formula      

    S = ( a + b + c)/2    where a , b , c is the side of triangle. 

    Area = [s(s-a)(s-b)(s-c)]^1/2

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Pericyclic Reaction//UGC/NET/JRF QUESTION

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Important points:-

1. Only heat and light is participating in the pericyclic Reaction. 

2. Not participating any reagents in the pericyclic Reaction. 

3. Pericyclic Reaction goes to constant mechanism. 

4. Intermediate from not make by Pericyclic Reaction. 

5. Pericyclic Reaction Mechanism explain by frantiyear molecular orbital [F.M.O].

Type of Pericyclic Reaction:-

                                                       Fourth type of Pericyclic Reaction. 

1. Electrocyclic Reaction 

2. Cycloaddition 

3. Sigmatropic Rearrangement 

4. Group Transfer Reaction 

1. Electrocyclic Reaction:-

1. It is one component system 

2. It is show the Intramuscular Reaction 

3. At the cost of one pie bond is one sigma bond

2. Cycloaddition Reaction:-

1. It is two components systems.

2. It is show the Intra and intermolicular both Reaction. 

3. At the cost of two pie bond ,two sigma bond is form.

3. Sigmatropic Rearrangement:-

1. It is one component system. 

2. It is show the Intramuscular Reaction. 

3. Not break of pie bond and not formation of sigma bond.

4. Group Transfer Reaction:-

1. It is two components systems. 

2. It is show the Intermolicular Reaction. 

3. At the cost of one pie bond,  one sigma bond is form.

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