Final answer:
Ba(OH)2 is classified as a strong base, HIO4 as a strong acid, HCl as a strong acid, Mg(OH)2 as a weak base, and C5H5N (pyridine) as a weak base.
Step-by-step explanation:
To classify each given species as a strong acid, weak acid, strong base, or weak base, we need to understand their definitions and recognize them either through their tendency to dissociate in water or by consulting a list of common strong acids and bases.
- Ba(OH)2 is a strong base because it is one of the few soluble hydroxides, such as NaOH and KOH, that dissociates completely in an aqueous solution.
- HIO4 (periodic acid) is a strong acid as it is a halogen oxoacid with more oxygen atoms than hydrogen atoms, which typically indicates a strong acid.
HCl is a strong acid as it is one of the six common strong acids that dissociate completely in solution, producing a high concentration of hydronium ions.
Mg(OH)2 is a weak base; it is only slightly soluble in water and does not dissociate completely.
C5H5N (pyridine) is a weak base; it does not fully dissociate and is less basic than the strong bases that completely dissociate.