Problem Solving Strategies - 2017-04-28 (page 4 of 5)

« first day (62 days earlier) ← previous day next day → last day (2579 days later) »

12:04 PM

3

Q: On reducing complex ODE's to Bessel's form using Kummer's series

I am trying to reduce the following ODE to Bessel's ODE form and solve it: $$x^{2}y''(x)+x(4x^{3}-3)y'(x)+(4x^{8}-5x^{2}+3)y(x)=0\tag{1} \, .$$ I tried to solve it via the standard method, i.e., by comparing it with a generalised ODE form and finding the solution from then on. The general form (...

differential-equations bessel-functions hypergeometric-function frobenius-method

oops sorry wrong room

lol

Anonymous

@NaveenBalaji You're from Bangalore? :P

Well that's what my SE page says

Anonymous

@Yashas Someone from your city :D

nope

I am not from Bangalore

I am from Mangalore :P

Anonymous

12:06 PM

@NaveenBalaji From IISC Bangalore? Your profile is impressive :)

Visiting student there

Anonymous

I see. Nice to see you. Wrong room though :P

yeah, is that Jee result out yet

people were going bonkers yesterday

Anonymous

@NaveenBalaji JEE Mains is out

Doesn't phenol react with sodium bicarbonate?

Resonance book says "If electron withdrawing group is present at ortho or paraposition of phenol, then it gives positive test with sodium bicarbonate"

Acid Amide + NaOH with heating => ?

Anonymous

12:10 PM

Any acid which is more acidic than H2CO3 will react with NaHCO3

yes

So you guys planning on doing engineering huh?

@blue pKa of formic acid is near 3.5 and pKa of phenol is around 10

Anonymous

@NaveenBalaji I plan on doing engineering or physics...not decided yet

Suggestion: Take Physics

Anonymous

12:12 PM

@Yashas So it won't react

Anonymous

@NaveenBalaji lol, why ? :P

I remember testing phenol with sodium bicarbonate in the lab :|

You'll have fun if you are into it, and its quite fascinating

Anonymous

@NaveenBalaji I'm more of the experimental type of person than a theoritical person....not sure if theoritical physics would suit me. Engineering physics seems quite interesting

Anonymous

@Yashas quora.com/Why-is-phenol-not-soluble-in-NaHCO3

Anonymous

12:17 PM

@NaveenBalaji Anyhow, thanks for the suggestion :) I think about it

Hello guys how do you plan to revise inorganic parts

Anonymous

Which class are you in?

Its the part which can guarantee me some marks

I am giving JEE this year :(

We will some day.

@blue It doesn't answer litmus paper either?

pKa of litmus is 6.5

But how to revise it? I mean I have done some chapters like Pblock, Sblock, but how to do qualitative analysis ?

Anonymous

12:22 PM

@samjoe If you haven't done even 50 percent till now...then sorry I can't guide you much.....

Anonymous

If you have done more than 50 percent

Anonymous

Then ask Yashas :P

@samjoe Metallurgy, Chemical Bonding, Coordination compounds

Anonymous

Chemical Bonding and Coordination are very important

I have done S, P and D block, and coordination too

12:23 PM

do chemical bonding and metallurgy

Anonymous

Qualitative analysis is very important too...but it is tough

do qualitative analysis at the end

Can I leave qualitative analysis part?

there is a good chance that you might forget before the exam

do it later

Anonymous

4/8 marks will be asked from qa for sure

12:26 PM

I mean i am not good in organic either

perfect physical chemistry

40% will be physical chemistry

@samjoe You might need at least a week or two to do a thorough study of organic.

Oh thats good then! I have still not revised electrochemistry and solutions.

Physical chemistry is important

it is easy and scoring

Yashas are tough questions asked from redox titrations and stoichiometry?

Those chapters are from 11 physical which i am not good at.

Anonymous

Those are conceptual chapters.

Anonymous

12:30 PM

Mole Concept 1 question is asked

@samjoe stoichiometry is important

redox reactions are also kinda important

Anonymous

Even redox is imp

you will have questions from d block involving redox reactions

Yes I can only solve basic problems, not the twisted ones. Are they asked?

Sometimes

Follow this order:

1. Stoichiometry

2. Redox reactions

3. Chemical kinetics

4. Atomic Structure (There will be few questions 100% - 10 marks)

12:32 PM

Thanks for information! Also one question in D block: I have done Trends + Manganese + Chromium compounds but I haven't done Tin, Iron, Copper, Silver compounds, are they even asked?

5. Thermodynamics & Thermochemistry (important chapter too)

6. Real gases (you already know about ideal gases I believe)

Anonymous

@samjoe Not so much.

it should take 1 hour to do a thorough study on real gases

7. Chemical Bonding

8. Coordination Compounds

9. Metallurgy

10. Solid State (hard to understand everything but questions are usually easy)

11. Solutions and Colligative properties (sometimes questions are not asked but scoring topic)

Anonymous

Electro!!

OMG

12:34 PM

Yeah

Electrochemistry!

do it before Chemical bonding

Thats why I missed it till now.

after Thermodynamics/Thermochemistry

u need thermo for electrochemistry

Equilibrium!

Chemical equilibrium questions are asked rarely

not so important

12:35 PM

oh

but you need to know the basic concept

because other lessons will need it

Yea I think Electrochemistry needs it

do Chemical equilibrium and Ionic equilibrium if you are not confident

it doesn't take much time

but other chapters will require it

and direct questions aren't asked in JEE

Anonymous

Ionic needs time

Anonymous

Lots of time

12:36 PM

If you have time, then do organic in this order:

In Ionic, I have learnt all hydrolysis and buffer formulas.. and did a couple of questions

1. General Organic Chemistry (Resonance, Inductive effect, etc)

Anonymous

Formulaes in Ionic are approximations

Anonymous

You need to know all derivations

@samjoe Don't learn formulae

you need to know the derivations

12:37 PM

Yeas I derived it and learnt the formulas

ionic is very easy

it isn't hard

2. Hydrocarbons

3. Aromatic Compounds

I mean like weak acid weak base.. etcetera ,, no for me it was tough really!

4. Alkyl Halides

5. Alcohols (easy chapter; takes 30 mins if you know alkyl halids)

6. Carbonyl compounds (important)

Hey how to study these chapters?

Anonymous

@samjoe Learn mechanisms.

12:38 PM

I mean do I have to know all about preparation or the reaction mechanism is only needed

Carboxylic acids and its derivatives

blue: And preparation?

the main problem in organic is that questions are asked such that it incorporates all the organic chapters

Anonymous

@samjoe Everything

Anonymous

You need to have indepth knowledge

12:39 PM

Alkane -> Alcohol -> Alkyl Halide -> Cyanide -> Acid -> Ester -> Saponification

that is an example question

Anonymous

You can go easy with physical

one question tests every chapter

Anonymous

But not with organic

so organic is hard if you do not know everything

if you have time, then do organic

so focus on physical chemistry

I mean like Theres a reaction in alkyl halide about hard electrophile soft electrofile.. I guess reaction with NaCN and AgCN.. are such reactions important for ADV?

Anonymous

12:40 PM

Yes!

then do important inorganic chapters

Anonymous

Ofcourse

I think my msgs were misplaced. The order is: physical chemistry > important inorganic chapters > organic chemistry

Anonymous

Hard Hard Soft Soft interaction is v imp

Hey friends another important question: SHould I study all subjects daily or like only a single subject one day?

12:41 PM

@samjoe focus on some topic

you will learn it in alkyl halide chapter

Hey is ACIDITY order important?

Anonymous

I study all per day

@samjoe in organic, yes

you might get a question

if you learn everything in half, then you are going to be in trouble

learn whatever you can thoroughly

I mean do we have learn the series of acidity that was given to me by my teacher, i mean it had alkanes, alkenes, alkynes, and other compounds, a general acidity list.

no

you should learn General Organic Chemistyr

Anonymous

12:43 PM

@Yashas Yes, that's good point

it will tell you how to determine the order

Anonymous

@samjoe You need to derive the series by yourself

nothing to memorize; just concepts to find the order

Anonymous

Learn GOC

@samjoe before doing organic do physical chem and important inorganic chapters

12:45 PM

But How do we know alkene is more acidic than alkane? Is it because negative charge is on more electronegative C atom? Someone told me that.

Anonymous

@samjoe Hybridization

@samjoe Yes, more electronegative carbon atom = more polarized the C-H bond is

Anonymous

Chemical Bonding

this increases the acidic property of the hydrogen

the carbon pulls the electron density of the hydrogen towards itself

Anonymous

Alkene has sp2 carbon....alkyne has sp carbon

12:46 PM

so to answer acid strength questions, you need to find the most polarized H - O or H - C bond

that involves a little bit of thinking

for which you should learn GOC

1

Q: Does vicinal dicarboxylic acid decarboxylate on heating?

Decarboxylation of carboxylic acid with electron withdrawing group on beta position generally decarboxylates on heating and the reaction proceeds through six member transition state. Does the same happen if the group on beta position is carboxylic group itself?

organic-chemistry reaction-mechanism

I studied decarboxylation in alkanes, as method of preparation.

Anonymous

@samjoe The answer is yes.

@samjoe If you are trying to remember the reactions then that is a terrible idea.

Learn GOC and Reaction Intermediates

you'll get answers to such questions automatically

I did revise carbocations and anions and radicals, but not thoroughly. But How can GOC help in that question? What kind of dark magic is this!?

Anonymous

@samjoe I don't mean to be rude, but please focus on the other entrance tests also apart from JEE Advanced if you feel (within) that you are not sufficiently prepared. Honestly, 20 days are too less but yeah, if you study smartly you can get a good score.

12:51 PM

GOC is the foundation of organic chemistry

Anonymous

@samjoe GOC is plain logic.

I see you guys have attained considerable amount of expertise in Chem-Fu

Chem-Fu?

I am still a rookie, even after spending much time on GOC

you haven't practised then

ignore organic for now

do physical chemistry and then important inorganic chapters

be thorough with them

12:52 PM

NOthing rude about that! I think I should also focus on BITs

ask for suggestions to learn organic after a week

BITs is waaaaay easier than JEE ADvanced

Yes that seems like a good plan for now! Thanks Yashas and blue!

Anonymous

@samjoe Good that you took it positively. :)

BUT I can't manage time also.. I'm pretty slow, and 150 questions in 180 minutes?

nobody can solve everything in 3 hours

12:54 PM

Sorry for troubling but how to revise maths also?

getting 50 questions out of 180 questions is pretty good in JEE Advanced

I did solve last 10 years questions from JEE archives

@samjoe Calculus is the most important.

Coordinate geometry

^ super easy and scoring

3D Geometry and Vectors

@blue @Yashas Is impulse , momentum and force related?

if you are good at those, you get get nearly 50% of the marks

12:55 PM

Yea I like those chapters and Vector, 3D is my strength

@Programmer Impulse = Change in momentum

@samjoe You will get 15 marks easily then.

You are probably good at algebra already so you needn't worry much about it.

Anonymous

@Yashas With 50/180 questions one doesn't qualify in adv

Anonymous

That's 27 percent

You don't get 180 questions lol

that's my mistake

50 out of 90 is good

BUt what about Algebra horror? Permutation Combination! Complex Numbers!

I am afraid of these

12:57 PM

@samjoe Study complex numbers

Also Properties of Triangles!

Anonymous

Forget triangles for now

@samjoe Ignore trignometry; can't master it so soon and it isn't important either

complex numbers is easy

^ blue: Everyone I met says that :)

learn Euler's formula

geometry of complex numbers

Learn matrices

6 marks 100%

12:58 PM

But Also I am weak in Binomial Theorem.

Yea Matrices and determinants is doable

Trigonometry is the part I am freaking afraid of... Its some type of lock&key problems. Isn't it?

not important

Binomial Theorem ^

Binomial they give a series of summation, in which they use some properties of coefficients

@Programmer Don't bother about trigonometry when you have just 20 days left

@samjoe It is differentiation

Anonymous

Binomial is super easy

Anonymous

12:59 PM

It's the easiest of the lot

I have 1 year 20 days @Yashas lol

Anonymous

P and C is tough

@samjoe (1+x)^n = nC0 + nC1 x + nC2 x^2 ....

@Programmer oops then do trignometry :P

differentiate both sides

Programmer can we switch lives :(

« first day (62 days earlier) ← previous day next day → last day (2579 days later) »

Transcript for

Apr '1728

Problem Solving Strategies

General chat for high school physics. For MathJax see [here](m...

fluid-statics homework-and-exercises newtonian-mechanics

join this room
about this room

00:00

06:00

12:00

18:00

all times are UTC

site design / logo © 2024 Stack Exchange Inc; legal

mobile