All Problems on CHARACTER TABLE in previous 5 CSIR Exams | Great Orthogonality Theorem
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- Опубликовано: 18 май 2018
- In this video we will try to get a brief knowledge of The Great Orthogonality Theorem (GOT)
and
Solved problems from past 5 CSIR Exams.
![Finding Total Number of Microstates [All Possible Types of Problems]](http://i.ytimg.com/vi/hCN6XhAMok4/mqdefault.jpg)
For JUNE 2017 Question on Character Table, number of unshifted atoms for C3 is mentioned 3 in the video but it should be 1.
Sir I have a difficulty in finding no. of unshifted aroms for sigma h, 2S3, 3sigma v. please help
Priyanka5685,
Number of unshifted atoms means during that Symmetry operation, how many atoms are not changing their position. Like you've asked for sigma h, so sigma h is horizontal plane and if we talk about BCl3 molecule then sigma h will bisect whole molecule including Boron and All chlorines in two parts, just like you bisect a apple using ur knife. Now when you bisect the molecule(that is when you apply sigma h) the atoms will not move from their relative positions thus number of unshifted atom is 4.
Now to compare this let's take case of C3 operation. Here we apply a three fold Axis which will pass through boron and all chlorine will move when we rotate by 120°, now here number of unshifted atoms is 1 that is only boron. Other chlorines are moving during the operation.
I hope it helped. 😇👍
thanks.. I was breaking my head. now it's OK.
thank you sir
thanx sir !!!! that confused me a lot...nd i was looking for this
In the question of csir June 2016 the number of atoms in the molecule is not mentioned. So we should take it 3 or 4 ?
In the last question you said we will multiply the ground state and excited state in this case we get the B1 in case if we don't any of them than what should we do???
Thanks a lot sir ☺😇 Your videos are really very helpful for us. The way u teach is really appreciable 👌👍 Stay blessed sir 😊😊
Thank You for the wishes and your kind words :)
Sir according to great orthoganlity theorem only sum of the square of identity is equal to order and all other character like C2, and sigma xz and sigma yz are not equal to order?
In the last proble, why we are multiplying A1 with B1, and we got a pettern same like B1, if we are getting a different pattern, what will do..?
Hi sir , can you post a video how to solve questions that are related to transitions allowed by x polarised light using character table
i was dumb at group theory but ur video made it simple for me
For last question if the transition is from ground state to A2...then what will be the answer?
Easy to understand.. thank you for your efforts sir.
You're welcome 😇
Sir.. Finding irred.representation take little bit more tym...any short trick to find it??
Many many thanks.
In BCl3 ques you told that degree of freedom 3N but how N is the order i.e h?.... we need to solve only for A1 ? Can you do one thing would you make short video of this question again? Is there any short trick for this?
There's no short trick for group theory... It is itself a very challenging topic.
I'll try to make a video to explain all these in more detail.
Sir pls describe the r represantion for more molecule like methan pcl5 SF5
very well explained Bro
A=A' as you mentioned and it contain Z2... so it can be raman active as we are only considering Z axis... both A" and A' involved Z axis, please make ot clear to me... rest is fine and no doubt its an excellent video and you made me learn the concept of Group theory.
How unshifted atom in 2c3 is 3? If we apply c3 axis dn all f shifts but B is not shifting
thats a mistake, I've given inthe comment also that it should be 1 not 3
Hello Sir, In the problem of June 2017, at the end you explained Z axis we will consider primary axis, my question is that This Z axis is going above and below the plane while initially in your lectures you consider y axis above and below the plane, plz tell me whether I am assuming right or wrong. Kindly reply. Thank you.
devendra mishra, you're correct that we consider y Axis going inside the plane of paper and z and x Axis on the plane but in the given question of 2017 June, we have three fold Axis along our usual Y Axis, but it is always taken as standard that the highest fold Axis should be along Z Axis,
So we have to consider the three fold Axis as the Z Axis.
why didnt you not Multiplied the coefficient of C2 and C3 at 18:22 ????
in BCl3 problem, why unshifted atoms for C3 operation is 3? should it be 1
we solved this problem in the class with our professor. I was checking my notebook when video plays and I see the same error. C3 should be 1. only Boron doesn't move.
Hi sir, for the bcl3 question, you said A1 is equal to A1 prime because is A1 is symmetric wrt to sigma h. So, A2 should also be equal to A2 prime because it's symmetric wrt to sigma h?
Choinu Lhouvum, yes absolutely correct A2 will be equal to A2 prime.
In BCl3 problem, why unshifted atoms for C3 operation is 3?
should be 1
You clear my biggest problem I feel so much relief
Glad to hear that 😊😇
Sir, in the first problem where we have found the characters,instead of solving, can we use orthogonality rule and we can rule out other 3 options, eventually left with option 1.
Yes you can
@@AllBoutChemistry ok sir...thank u sir😊
Sir your videos are very helpful to me can you plz make a video on statistical thermodynamics and previous year questions on it?
Thank you 😇
OK ill try to make a video on statistical thermodynamics. 👍
what if there is improper operations i.e S3? what will be the unshifted atoms?
simran kaur, you perform that operation and then check how many atoms are not shifting. It's difficult for me to explain by writing here. There will be only boron which will not shift when you perform S3. S3 is combination of C3 and sigma h. Just apply C3 followed by sigma h
ok thankyou for your reply sir
You're welcome 😇
U r fantastic Sir.Accept my love ,care and respect sir.Sir plz application part if Mass spectroscopy
thank you brother for your kind words :)
I'll try to make a video in mass spectra
Sir in case of June 2017 question why only last option is correct..how come only A2" is considered..what has the orientation of Cl and B molecule to do with the answer..I am not able to understand that part..why is it that axis is along z axis it could be x or y.. please help
Fatima Tufail,
As per given in the question, the molecule is not stationary, it's undergoing Vibrational motion as per given sign in question, that is, + denoting the molecule coming out of plane and - denoting going inside the plane. Now our principle Axis is C3 which is passing through boron and by default we always take C3 Axis along Z direction. Now if you'll see the Vibrational motion that is happening in the direction of Z-Axis, which means for this particular question we have to consider that option which has only Z Axis in it. As you must have seen that all other options were also correct but since molecule is vibrating in Z axis so we will take this. Now if the molecule would be stationary that means without any vibrational motion then all options would be correct.
I hope it helped 👍
All 'Bout Chemistry thank you so much for your prompt reply..it helped greatly..keep up the good work 🙂🙂
Fatima Tufail, you're welcome 😇
Keep watching and keep sharing our videos 😊
Sir, you made it so simple to understand. I was trying to understand from the book but was failed to understand. I want to ask
that there are two more rules for GOT, Are they important from exam point of view??
Jolly Balel, yes there are two more rules but I think these are enough for solving questions in CSIR.
@@AllBoutChemistry hello sir , could you plz refer a book (other than Cotton) to grasp the Group theory concepts as well as mastering the problem solving approach ?
very helping sir thanks a lot
Sir, why NUSA in C3 axis of BF3 is written as 3. I may be wrong, but so far I understand NUSA for C3 should be 1. Please clear me this point..
Yeah.. you are absolutely 👍 right
Good job sir 👍
thanks sir. plz make a video biorganic chemistry
Sir kindly solve the problem given in this video at time 26.33, though you said this is simple problem but I could not solve it. Thank you.
Thank u so so much sir...
For solving my prblms...
N for considring my request...
☺☺
You're welcome.
All the best for CSIR Exams
All 'Bout Chemistry ..... thanks for ur best wishes sir.
Thank-you sir
Sir
No of unshifted atoms in C3 should be 1
Because 3 atoms changing position and 1 not
Then why you wrote 3?
Pls explain sir
Nice video Sir.
Sir one small obligation... Is this video is sufficient for beginners like me for understanding this concept better....
sir point group for equilateral triangle= D3h and for isosceles triangle= D2d?? Is it right or wrong?? plz reply
for equilateral triangle is correct but for isosceles triangle it should be C2v
thanks a lot sir 😊😊
You're welcome 😇
thank you sir
Hello sir pls tell me the answer of gate 2005 group theory qyestion. The orbital 1sHA -1sHB of water belongs to the irreducible representation ? A) A1 B) B1 C) A2 D) B2
Thanku sir so much seriously a huge thanks
You're welcome 😇
Sir plss help me ...I can't understand the difference between the sigma v plane and sigma d plane
Watch my video on Basics of Group Theory
sir plz....... makes video on symmetric top molecules and spherical top molecule.
In the BCl3 problem, A1' should also be Raman active nah? It has a z2 term.
Yes its raman active, but there is the involvement of dx2-y2, it is not correct
Nice videos all 💓
unshifted atom corresponding to C3 axis will be 1 not 3.check it please.
yes,,sir,,please check it
Thanks really very helpful video
You're welcome 😇
Thank you so much sir....
You're welcome 😇
👍👍👍👌👌
Sir please tell me what is the contribution of dihedral plane
it will be similar to vertical and horizontal plane only.
Thanks
Nice explanation sir....but I think no of unshifted atoms for C3 will be 1....you have written 3....in huheey also it is given 1....
Yes you're correct, it should be 1, actually it get multiplied with zero to form RR, so that eventually didn't bothered in the solution so I didn't got that mistake... Thank you for pointing it out... 👍
Sir...there is one more question in June 2016 paper...regarding D3 point group...
The ans of your second last question is - option B
Ques - 1: No. of unshifted atom in pyridine?
Ques - 2: In the vibrational spectrum of CO2, the number of fundamental vibrational modes common in both IR and Raman are ________________? a) three b) two c) one d) zero
Ques - 3: 2C3 and 3C2 in these how found the unshift atoms pls elaboately? Sir, If there is any disturbance for u, beacuse of asking so many doubts in various video?
It's difficult for me to explain all your doubts here.
Number of unshifted atoms in pyridine is not correct question bcoz you have to specify that which operation you are performing then only number of unshifted atoms can be calculated.
Number of unshifted atoms can be found in C3 or C2 not in 2C3 and 3C2
in C3 axis of rotation or C2 axis of rotation Numbe r of unshifted atom depends on molecula and fromwhere you are passing axis, like in H2O we pass C2 axis from oxygen so number of inshifted atom is 1
while in cis but-2-ene we pass C2 axis from between of C=C bond, thus number of unshifted atoms is 0 there.
Thank u
Sir u don't multiply with cofficient of symmetry elements in order to find character of ir time 19:00
Oh , Sorry sir u corrected it afterwards
Sir plz tell me the ans of june 2016... My ans is 2A1 + 3E
❤❤❤
pls giv the answer for c3v qstn in csir june
Ans is 2A1+2E
The answer is optio 1 which u said to solve of correct pls reply
Thank you 👍👍
you're welcome
no of unsifted atom for c3 is =1 not 3..
Can you please make a video on d4h point group
I already made video on point group and I've discussed this there. Please watch that.
Just type Point group allboutchemistry in the search bar and you will get that video
Ok sir thanku sir
Thanks a lot
You're welcome 😊
Very good noorul
thank you bhai
Thanks sir
You're welcome 😇
Option b is correct in que of June 2016
I solved that question I get. Answer 2 is right
very good
How u wrote unshifted atoms
Is there any trick to solve it quickly
No we have to apply the operations on the molecule in our mind..😓
Sir series of organic chemistry related to csir net
Alright 👍
Thank you sir.. Total degree of freedom is 3N.i.e 12. But when we add coefficient of all rotational vibrational and translational motion it comes out to be 8. Plz help
Nisha Leo, very good question.
Well in the mulliken symbols we use E for two dimensional Symmetry. Now you have E prime and E double prime.. If you count them 2, then overall you'll get 12.
Thank you for reply..
Rotational =A2'+E"=1+2=3
Translational = E'+A2"=2+1=3
Vibrational = A1+2E'+A2"=1+2(2)+1=6
Total = 12vibrations
Sir is it correct or not. Plz do tell and thank you very much
Nisha Leo, yes correct 👍
Thank you sir for your guidance.
Most welcome 😇
And...sir pls take some more topics on physical chemistry.... Kinetics, physical spectroscopy, thermodynamics and quantum....please sir..take last 2 CSIR exams atleast...
Alright 👍
Thank you sir
Sir plz solve this question also june 2016 C3v
which question you're asking?? plz specify set and question number.
a1 double prime ki value nhi likhi
Sir m.sc.chemistry 1st SEM 2016 and 2015 ke paper plz send kre
Rule 1 - said that no of IR in a point group is equal to no of classes.
Not equal to order according to you.
Nuclear chemistry par series
alright
C3 should be 1.
Sir, please solve cis butadiene character table csir december 2014
that's vrey easy question. but it's difficult to make a dedicated video for that, you can ask where you are getting trouble while solving that problem, I'll help you out.
👍👍👍👌👌