CSIR, GATE, JAM, IISc, and all other Chemistry Higher studies Exams has been changed their syllabus. If we analyze them quite precisely and it’s seems that many advanced are of research has been included. The previous year’s questions from those type exams are clearly indicated that, students must understand the fundamentals, and they must have reasoning ability to answer the question. In this view we wish to collect most important exam based reasoning questions and we discussed answer for them. It’s not only useful for competitive exams also for your interviews.
Often resonance effect based questions are raised in all chemistry compettive exams.
For example:
Give reason: phenanthrene have more stabilization energy than anthracene?
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyOGTmwNfyR9QSz0tneok-7tmpVfWr3N-GCEJsYGqnIKWaIvp0T7SbHRFt4GKyxU1SDxvQHbmcuNVpuD7x56iE2O3yVNK0ojY6Z7HIq8jHiMyLBKKOwhiJBaWH9266Bu2mP7vRB4hB7Fyr/s1600/anthracene.bmp)
Answer:
In general, for compounds containing equal numbers of benzene rings, that for which the greatest number of Kekule structure can be drawn has the largest stabilization energy.
Due to higher number of phenanthren resonance forms, it has more stabilization energy.
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Anthracene Resonance Strectures |
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Phenanthrene Resonance Strectures |
Tomorrow we will see some other reasoning questions.
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