(a) The reaction of chlorine with hot and concentrated NaOH solution gives sodium chloride and sodium chlorate.
3Cl2+6NaOH(cold and dilute)→5NaCl+NaClO3+3H2O
(b) All the five bonds of PCl5 not equivalent. PCl5 molecule has trigonal bipyramidal structure. Three equatorial P−Cl chlorine bonds are equivalent. Two axial P−Cl bonds are longer than equatorial bonds. Axial bond pairs of electrons suffer more repulsion than equatorial bond pairs of electrons.