* Surface Area: Crushing limestone increases its surface area significantly. The reaction between an acid and limestone occurs at the surface of the limestone particles. More surface area means more contact points for the acid to react with, leading to a faster reaction.

* Accessibility: The acid can now reach the limestone more easily and quickly. Imagine trying to dissolve a large, solid chunk of limestone – it would take a long time. But if you crush it into smaller pieces, the acid can access the entire surface more readily.

Think of it like this:

Imagine trying to dissolve a sugar cube in water. A whole sugar cube will dissolve slowly. But if you crush it into smaller pieces, it dissolves much faster. The same principle applies to limestone and acid.