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1. ### -R effect in benzene causes anti-aromaticity?

Consider any -R effect showing group like NO2 in place of anyone of the hydrogen of the benzene ring, here we get nitrobenzene. We know that after showing -R effect a double bond will be formed between N and C and one of the π bond will no longer be present in the ring and it's place will be...
2. ### B A function's derivative being not defined for some X but having a limit

Are you saying that derivative not being defined at X=0 also implies that the function is not defined at X=0?
3. ### B A function's derivative being not defined for some X but having a limit

Let's say I have a function whose derivative is (tan(x)-sin(x))/x. It is not defined for X=0 but as X approaches 0 the derivative approaches 0, so should I conclude that my function is not differentiable at X=0 or should I conclude that the derivative at X=0 is 0.
4. ### B Is there a condition for applying standard limits?

The answer using polynomial expansion of ln(1+X) and sin(X) in numerator is 1/2 as numerator is X3/2 + higher powers of X, which(those higher powers) tend to 0 and by putting tan(X)=X and sin(X)=X in the denominator, the denominator becomes X3 which gives the right answer. But I am asking why...
5. ### B Is there a condition for applying standard limits?

I came across this basic limits question Ltx->0[(ln(1+X)-sin(X)+X2/2]/[Xtan(X)Sin(X)] The part before '/'(the one separated by ][ is numerator and the one after that is denominator The problem is if I substitute standard limits : (Ltx->0tan(X)/x=1 Ltx->0sin(X)/X=1 Ltx->0ln(1+X)/X=1) The...
6. ### Why is a Hexagonal Prism Used as the Unit Cell for 3D HCP?

My textbook states that all the 14 bravais lattices have one of the 7 types of parallelepiped (7 crystal systems) that can be used as an unit cell. However in case of 3D HCP textbooks don't talk about this parallelepiped, rather they consider a hexagonal prism as the unit cell. Why is it so...
7. ### Phase diagrams for fractional distillation

Yes but not much about the behaviour of such mixtures.
8. ### Phase diagrams for fractional distillation

So that means that for a mixture heat at the boiling point does increase the temperature apart from being used as latent heat for phase change ? If yes, then why is it so? And corresponding to a specific composition having a specific boiling point, how to tell how much of the liquid will...
9. ### Phase diagrams for fractional distillation

https://www.chemguide.co.uk/physical/phaseeqia/idealpd.html#top I learned about phase diagrams involving partial Vapour composition, temperature and composition of binary solutions from this website. You can find it if you scroll down to a little above the end First it considers a binary...