Foundation4 past questions

Bond Enthalpy and Dissociation Energy

Bond enthalpy is the energy required to break a bond in a molecule, influenced by bond order, hybridization, and s-character.

Why this shows up in the exam

You need to compare bond strengths and predict trends in bond dissociation energies.

How NEET tests this

Statement analysis · 2 QsApplicationMatch the columns

Practise it

These are real questions from past NEET papers that test this exact idea.

Question 1 of 4NEET 2003

Which one of the following statements is not correct for sigma- and pi- bonds formed between two carbon atoms? (a) Sigma-bond is stronger than a pi-bond. (b) Bond energies of sigma- and pi-bonds are of the order of 264 kJ/mol and 347 kJ/mol, respectively. (c) Free rotation of atoms about a sigma-bond is allowed but not in case of a pi-bond. (d) Sigma-bond determines the direction between carbon atoms but a pi-bond has no primary effect in this regard.

Push further

More challenging

9 harder questions built from the past papers above — a step up in difficulty, with distractors designed so you can't get there by elimination. Written and checked by our reviewers, not from a real paper.

Question 1 of 9

In the molecule N2 (nitrogen gas), the bond between the two nitrogen atoms is a triple bond. Given that the bond energy of a N≡N triple bond is 945 kJ/mol and a N-N single bond (sigma only) is 163 kJ/mol, what is the approximate average energy of a single N-N pi bond in N2?