Opt
IiTeachChem
•Created by Opt on 4/15/2025 in #💭│doubts
Mechanics doubt
Could someone explain the Virtual Work Theorem to me? The ΣTiai = 0 thing hasn't made sense to me at all, and my teacher didn't even teach it last year. I couldn't even find it in any of my go-to books, and whenever I look up 'Virtual Work Theorem', I get the d'Alembert concept of virtual displacements, which is not what I want.
22 replies
IiTeachChem
•Created by Opt on 4/3/2025 in #💭│doubts
Last minute chem doubts
I'm blanking like hell here so, couple of rapid fire doubts.
1. What are the deciding factors for melting point and boiling point of compounds? Specifically substituted benzenes.
When does dipole moment come into play and when is it important to consider H-bonding?
2. For hybridisation of orbitals (or LCAO, whichever one you prefer), how does one decide which orbitals hybridise from a given set?
Eg: For a sp³d hybridisation, can we know which d orbital is chosen? The d orbitals are initially degenerate so, what criterion applies?
I thought I had these in notes, but apparently I don't. 🤷♂️
35 replies
IiTeachChem
•Created by Opt on 1/28/2025 in #💭│doubts
Series involving binomial coefficients.
59 replies
IiTeachChem
•Created by Opt on 1/16/2025 in #💭│doubts
Binomial theorem/Series
I need help with questions 7 and 18.
How does one solve these? I multiplied (1+x)³⁰ and (1-x)³⁰ for Q7, but got stuck midway. For Q18, I got 0, but the answer is -30C15. Idk where I went wrong.
14 replies
IiTeachChem
•Created by Opt on 1/15/2025 in #💭│doubts
Limits
Let's see if I remember how to type this out.
$\lim_{x \to 0}\frac{cos(sinx)-cosx}{x^4}$
I tried series expansion, and got somewhere, but it didn't work out in the end.
56 replies
IiTeachChem
•Created by Opt on 12/8/2024 in #💭│doubts
Ionic Equilibrium.
Few small doubts.
1. When do we neglect terms like 1±α? How much does it impact the final answer?
2. When do we factor in the contribution of auto-ionisation for calculating pH of a solution?
16 replies
IiTeachChem
•Created by Opt on 6/7/2024 in #💭│doubts
Electronic effects and Reactive Intermediates
I began revising the topic and can someone explain why cyclopropyl methyl carbocations are more stable than benzylic carbocations? There are no π-electrons in the cyclopropyl group to move towards the (+) charge on the methyl like in a phenyl group, so I don't get ir
12 replies