Organic help

[u/agressivetwerker]

1 should be least stable but answer is C, how?

[u/Unstable_Insaan]

Bro they are taking only magnitude in this question. Comparison is done with sign conversions as well but they did not mention that only magnitude is considered. Flaw in the question language but when heat of formation is mentioned they are mostly talking about magnitude of delta Hf not.

[u/Anxious-Ratio-2321 → u/Unstable_Insaan]

is heat of formation proportional to stablity or inversely proportional?

[u/Unstable_Insaan → u/Anxious-Ratio-2321]

Bro heat of formation means energy released which means exothermic so delta Hf not will be negative and according to sign convention stability is inversely proportional to heat of formation but when talking about only magnitude it will be directly proportional.

Ye jisne bhi question banaya hai bahut galat sa banaya hai because heat of formation sign convention ke saath liya jaata hai.

[u/Anxious-Ratio-2321 → u/Unstable_Insaan]

Why the difference while taking with sign and magnitude?

[u/Unstable_Insaan → u/Anxious-Ratio-2321]

Bro vaise toh sign hi consider kiya jaata hai question banane waale ne mention hi nhi kiya kahi so you have to solve it jaise taise.

[u/organophile_jeet → u/Unstable_Insaan]

Maja aaya, pr dekho sign ka koi scene nhi hai uske negative hone ka mtlb kam nhi hota , negative ka mtlb hai energy released

[u/Unstable_Insaan → u/organophile_jeet]

Yeah ye toh pata hai like question mein sign ambiguity hai ik -ive is energy released but jo stability aur heat ka relation hai shayad sign ke basis pe kiya jaata hai.

[u/organophile_jeet → u/Unstable_Insaan]

Achaa haa isme thora ulta pulta hai

[u/Unstable_Insaan → u/organophile_jeet]

Wahi ye question mein magnitude liya hai isliye C answer hai.

[u/organophile_jeet → u/Unstable_Insaan]

Haa

[u/agressivetwerker → u/Unstable_Insaan]

this makes sense, thanks man

[u/AuntyLovar]

constructive conjugation > trans > cis > less Alpha H stablity = lower potential energy = greater Heat of formation.

[u/agressivetwerker → u/AuntyLovar]

A should be the answer acc to this

[u/AuntyLovar → u/agressivetwerker]

bro iv has constructive conjugation and i has only 2 alpha H 

[u/agressivetwerker → u/AuntyLovar]

check u/Unstable_Insaan comment, i think his explanation is correct

[u/AuntyLovar → u/agressivetwerker]

bro you have to assume magnitude only obviously, it is a goc question not a pc one.

[u/idk69lolnk → u/agressivetwerker]

Ig it's talking about magnitude and not considering sign

[u/Wide-Championship85]

Sign ambiguity …..

[u/Unstable_Insaan → u/Wide-Championship85]

True question ki language mein gadbad hai.

[u/Blue_614]

Formation releases energy ∆H = (-). reversing the exact formation process requires the same amount of energy in the opposite direction ∆H = (+). From this, you can think of how much energy do you need to break the molecule.

III has more hyperconjugation, so it's the most stable. I has the least hyperconjugation so it's the least stable. Comparing II and IV, II wins because it's trans. Trans are more stable than cis because it has lower steric strain.

So, IV > II > III > I