Which relations are not correct for an aqueous dilute solution of `K_(3)PO_(4)` if its degree of dissociation is `alpha`?

Is the given relation correct for an aqueous dilute solution of K_(3)PO_(4) if its degree of dissociation is alpha ?

The pH of a 0.1 M aqueous solution of a weak acid (HA) is 3. What is its degree of dissociation ?

For a very dilute aqueous solution of H_(3)PO_(3) van't Hoff factor

What will be the dissociation constant of 0.1 N aqueous ammonia solution in terms of degree of dissociation 'alpha' ? What will be the value if the concentration is 0.01 N ?