Answer:
Breaking up the solid increase its surface area which speeds up its dissolving ability.
Explanation:
The speed of a solid dissolving in a liquid depends upon:
1. Temperature
2. size of the solid particles
3. stirring
With increase in temperature, stirring and decrease in the size of solid, the speed of dissolving increases.
By breaking the solid into smaller particles, the surface area increases. More the area of contact with the solvent particles, more would be the speed of dissolving.