Chapter 15, Problem 12PE

Explain why one acid is weaker than the other in the following pairs: (a) ${\text{H}}_{\text{3}}{\text{PO}}_{\text{4}}$ and ${\text{H}}_3{\text{AsO}}_{\text{4}}\text{,}$ (b) ${\text{HIO}}_{\text{4}}{\text{and H}}_{\text{2}}{\text{TeO}}_{\text{4}}$.