Find the equivalent weight of `H_(3) PO_(4)` in each of the following reactions:
`H_(3) PO_(4) + OH^(-) to H_(2) PO_(4)^(-) + H_(2) O`
`H_(3) PO_(4) + 2OH^(-) to HPO_(4)^(2-) + 2H_(2) O`
`H_(3) PO_(4) + 3OH^(-) to PO_(4)^(3-) + 3H_(2) O`

Explanation

98, 49, 32.67