Question

Why are hydrogen atoms in acetylene more acidic yhwn those in ethylene?

Answer 1

So It is more penetrated to the nucleus… so the electrons in s orbital are more attracted to the nucleus. and so In a way the electronegativity of the element having more s character is more. So C in ethyne is moreelectronegative than in ethene… and therefore Hydrogen in ethyne is more acidic than in Ethene!

OR

acytelene has sp hybridisation and ethylene has sp2 hybridisation.so acytelene has more 's' character. hence bonding electrons are nearer to nucleus.i.e., the electronegativity of carbon is more. hence the bonding electrons(c-H in acytelene) are moves towards carbon. thus we easily remove the H as H+ with base. hence acytelene is some what acidic.but due to the less s character in ethylene it does not show acidity

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