Advices For Studying Organic Chemistry

4) Highest amount of positive charge at the hydrogen of hydrogen fluoride (pKa =

3.2).

Figure 3.2 The effect of increasing electronegativity among elements from left to
right in the first row of the periodic table is evident in these
electrostatic potential maps for methane, ammonia, water, and
hydrogen fluoride.

Basicity increases

CH 3 − H 2 N− HO− F−

3.7A THE EFFECT OF HYBRIDIZATION

1. The acidity of ethyne, ethane, and ethane:

HHCC CC

H

H

H

H

CC

H

H

H H

H

H

Ethyne Ethene Ethane
pKa = 25 pKa = 44 pKa = 50

1) Electrons of 2s orbitals have lower energy than those of 2p orbitals because

electrons in 2s orbitals tend, on the average, to be much closer to the nucleous

than electrons in 2p orbitals.