Sunday, May 27, 2012

My Exam#3

My semester exams are over :) :)

My first three exams were good. But, the last three.. I don't feel that they were good  :( :(
My Microbio exam and BIBT exams were good.
After that even my unit operations paper was good. But, this mathematics... :( :(
Maths is my weakness :( :( I make lots of careless mistakes :(
In maths this time I had Probability and statistics, mm.. I'm worried a lot about the results.
Then other papers were, Chemical and bio thermodynamics ; Instrumental methods of analysis.

Let's have a glance at the questions which I found different or can say difficult.

Topic: Instrumental Methods of Analysis:
Question 1: What information can be obtained by DTA that cannot be obtained by TGA?

Know the basics about DTA and TGA :

Answer is :
DTA gives information  such as Glass transition temperature, crystallization, sublimation which can't be obtained from TGA curve.

Question2: Advantages of Raman Spectroscopy over Infra red spectroscopy?

1) Raman spectroscopy gives detailed information about the backbone structure of the molecule whereas infrared gives indicates only polar segments.
2) It can be used to study materials in aqueous solutions, because infrared radiation is poorly transmitted by aqueous solutions.
3)Infrared is scanned using different instruments for near infrared, mid and far infrared, but, in Raman spectroscopy single instrument is enough.
4)In Raman spectroscopy, scattering power is directly proportional to concentration, whereas in infrared, absorbance is directly proportional to concentration.
5) Sample preparation is very simple in Raman Spectroscopy.

Topic: Chemical and Bio Thermodynamics:

I was asked a two mark question: What is host work?
Carnot heat engine 2.svg
I don't know the answer for this, if you know, kindly let me know.
All the other questions were simple in this paper.

Have a good time :) :) :) BYE! BYE!