Key Idea Oxidation state of H is + 1 and that of
O is - 2.
Let the oxidation state of P in the given compounds
isx.
In $ H_4 P_2 O_5 $
$ ( + 1) \times 4 + 2 \times x + ( - 2) \times 5 = 0 $
$4 + 2x - 10 = 0$
$2x = 8$
$\therefore$ $ x = + 4$
In $ H_4 P_2 O_7$
$ ( + 1 ) \times 4 + 2 \times x + ( - 2) \times 7 = 0 $
$4 + 2x - 14 = 0$
$2x = 10$
$\therefore$ $ x = + 5$
Thus, the oxidation states of $P$ in $ H_4 P_2 O_6, \, H_4 P_2 O_6 $
and $ H_4 P_2 O_7 $ are $+3, + 4$ and $+5$ respectively
P block elements are those in which the last electron enters any of the three p-orbitals of their respective shells. Since a p-subshell has three degenerate p-orbitals each of which can accommodate two electrons, therefore in all there are six groups of p-block elements.
P block elements are shiny and usually a good conductor of electricity and heat as they have a tendency to lose an electron. You will find some amazing properties of elements in a P-block element like gallium. It’s a metal that can melt in the palm of your hand. Silicon is also one of the most important metalloids of the p-block group as it is an important component of glass.