TOUGH TIME AHEAD (NEED TO BE SPECIFIC FOR Dec NET): Good evening to all. The 22nd June NET is over and many of aspirants are feeling relaxed and relived after a huge hard work for the exam. For few days after the exam, I received large number of messages and phone calls regarding probable merit and when I asked many of these people regarding the probable marks that they met get, I got variable figures however majority of them were lying in between 80-100. When I asked the students regarding their comments about exam, most replied it as very tough, few said tough while remaining very few said it was good. As I really don’t know the cut off of this exam, I personally feel it would be around 90 for LS and 100 for JRF. But when I was student and was appearing for these exams (there were no social networking sites in those days), I always use to believe that cut-off will be at least 10 marks less that what I am going to get. This is because my teachers taught me positive thinking and thus when I use to think in this manner, I use to feel relaxed and relived. Its good to think this way than worrying thinking that cut-off will be more and I may not probably reach there this time. I asked for question paper of June 2014 from my students just to see the level of questions and I was really shocked to see it. I found many of questions in June NET which were highly specific. There use to be very less questions of this type in previous NET exams. This time there number was bigger one. I thought to share my thoughts regarding such questions. I believe that questions are of two types: General and specific. Let us see the meaning of general questions: For example, when I started learning Shapiro reaction, I came to know that it involves conversion of ketones into olefins using tosyl hydrazine and organolithium bases. I came to know that there is formation of double bond in between carbonyl carbon and adjacent less substituted carbon. CH3COCH2CH3 is thus get converted into CH2=CHCH2CH3 and this made my chemistry easier. I use to think this trick whenever I use to solve Shapiro problems i.e. formation of olefinic double bond between carbonyl carbon and adjacent less substituted carbon and this trick helped me to solve large number of problems very easily. Thus, I had a general solution for Shapiro problems. The second category called as specific questions is really very difficult. I remember Chichibabin reaction for this which involves amination of azaheterocycles such as pyridine, quinoline, isoquinolines, etc. This is one of the rare nucleophilc substitution reaction of aromatic species where NH2 anion attacks at Carbon attached near Nitrogen yielding product. When I seriously thought the mechanism, I followed that NH2 anion attacks carbon attached to nitrogen because this carbon bears electron deficient nature as compared to other carbons. I thought I got basic trick which is in consistent with chemistry basics i.e. NH2 anion attacks on electron most electron deficient carbon in the rings during Chichibabin reaction. I had seen few examples in some common text books regarding chichibabin reaction and was very happy that this trick was working. One day, I found a review on Chichibabin reaction and I was shocked to see the review. There were hundreds of examples on Chichibabin reaction which I had never seen earlier. In many of examples in review, NH2 anion attacked at unacceptable positions in the azaheterocyclic ring meaning that it has attacked less electron deficient carbon when more electron deficient carbon was available in the same molecule. I was confused as there were several such examples. I went to Prof. Wadia (One of the most intelligent and efficient teachers of modern times in India) who is Professor at Pune university. I asked him regarding the discrimination of NH2 attack on the carbon. Prof. Wadia gave a big smile to me and said that sometimes in Chemistry, the reactions occur without following rules of chemistry and he referes such reactions as observed reactions. As an example, he said that if some day somebody asks u why human beings have only two hands then you must reply human beings have two hands because they are observed. Meaning for some questions, answer is that it is observed. The biggest difficulty in solving these observed reactions which I call specific reactions is that you cant solve these until you have seen such a reaction. If you try solving such reactions, you arrive at wrong conclusion. I have seen many such specific reactions in June 2014 NET paper. These questions are warning/alerting us something. They are saying us to expand scope of our reading. Thus reading few books is not going to help us now. We need to start reading broader literature of chemistry so that such specific questions will no be skipped by us. This can be done by reading standard books, reviews, etc. I remember beautiful phrase from alchemist where the boy says “I must start reading big books now for two reasons that they last longer and make good pillows”. I think we need to take lesson from this. We must start reading big books now for two reasons that they will help us to solve specific level; questions and thus to pass NET. AND If you have planning to read big books after reading this post, start it today as tomorrow will be too late as we have few months and list of books is large and also it is said “Seize the day, put no trust in tomorrow”. I am soon starting guidance lecture series at Capital cities of all states from August. I will tell u regarding schedule of the same. These lectures will be free to all. There will be no fees for them.
Posted on: Sun, 13 Jul 2014 13:51:33 +0000
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