(a) I > II < III > IV < V
(c) I > II > III > IV > V
(b)V > IV > II > III > I
(d) V > IV > III > II > I
Basicity is the tendency to give electrons and factors affecting basicity are :
1) Electronegativity along the period -More Electronegativity atoms do not want to give electrons so easily .Along the period basicity decreases as Electronegativity increases.
2) Size down the group -Big atoms with big orbitals can hold electrons nicely with minimum electron -electron repulsions. So down the group as size increases basicity decreases.
3) Electron density delocalizes due to resonance and hence it also makes it less basic.
4) Presence of electron releasing groups or donating groups can increase the basicity .
5) Presence of electron withdrawing groups can increase the basicity.
Checking all these factors :
Most basic is V (N is least electronegative)
Least basic is Cl-(big atom and its conjugate acid is also very strong acid HCl )
RCOO- has resonance and RO- has Presence of electron releasing groups or donating groups.
Now try to arrange the order