Question

6. For the following groups of molecules where the circled H's are the most acidic protons, circle the one with the lowest pka value. Η Η , ο Η Η, Η H, X.LH ΗΣ ΧΗ "H H H "" Η Η Η, Η ' o= Χ II II II XXH Η Η Η II ΠΗ Η Η Ι I Η Η. Η Η: Η Χο. Η нннн Λ. Η Ο Η

Answer 1

Acidity of hydrogen increases when it will attal highly electronegetive atom are the stability of Congo is higher than others, it will attached with a ability of Conjugate base H H H H H HiH oH NH # *** LCD ħ H'H(A) H H (B) Electronegctivity of oxygen is higher than nitrogen which has high electronegetivity than Carbon. Hence Acidity of Hof (e) is highest & Pka is lowest. H H H YOH(D) HH () - 2002 Resonance noo Stabilized Conjugate 'l base Therefore @ has most No resonance stability of Conjugate base. acidic proton. CerSH «Ht. IT (H) (conjugate base) ra) (conjugate base)

1_ WUU ho Ht OH OSK Tero (I) ( Resonance Stabilized Conjugate base) As stability of Conjugate of (1) is higher than others. so Pra of I is lowest & it is most acidic.