Which is a stronger base?
a. HS− or HO− c. CH3OH or CH3O− e. CH3COO− or CF3COO−
b. CH3O− or d. Cl− or Br− f. CH3CHClCOO- or CH3CHBrCOO-
Here we have to find out which is stronger base among the given molecules.
It is known that the relative acidity depends on the following two factors:
1. Atomic size
2.A Stronger base has weaker conjugate acid.
a. HS− or HO−
Here the bases HS- and HO- are formed from its conjugate acid H2S and H2O. Here H2S is the stronger acid than that of H2O due to the presence of S-atom, which has big atomic size than O-atom.
The conjugate base of the strong acid is less basic, thus HO- is the stronger base than HS-.
b. CH3O- or CH3NH-
Here the bases CH3O- and CH3NH- are formed from its conjugate acid CH3OH and CH3NH2. Here CH3OH is the stronger acid than that of CH3NH2 due to the presence of more electronegative O atom.
The conjugate base of a strong acid is less basic, thus CH3NH- is the stronger base than CH3O-.
c.CH3OH or CH3O-
CH3O- is the conjugate base of CH3OH. Methanol is very weak acid because it has very low dissociation constant. As it is known that the weak acid has stronger conjugate base thus CH3O- is a stronger base.
d.Cl- or Br-
In order to find the stronger base, we have to find out...