How could you safely determine if a base is stronger than an acid?

If you compare an acid's pKa and a base's pKb, the thing with the lower value is “stronger” in terms of acid or base. If you mix equal amounts of a base with a lower pKb with a substance that has a higher pKa, the resulting solution would be acidic.

Explanation:

If you’re trying to observe a battle of wills between an acid and a base, whichever one forms a solution (of equal molarity and volume, in deionized water) with a pH further away from 7 is stronger. I say equal molarity and volume because this means that an equal number of ions of each substance would be floating around in an equal amount of water.

a polar bond is formed when electrons are shared unevenly between atoms