Exercises: Collision theory

An effervescent tablet takes a while to dissolve in a glass of water. Predict whether it will dissolve faster whole or crushed, and explain your answer using collision theory.

Milk sours (because of bacterial action) within a few days if it is left out of the refrigerator, but it lasts much longer inside it. Explain, using collision theory, why temperature changes the rate of that decomposition.

In flour mills and tortilla factories, flour dust hanging in the air is a real hazard: a single spark can trigger an explosion, while a sack of packed flour barely burns. Explain the difference using collision theory (think about surface area and the concentration of particles) and propose one safety measure consistent with your explanation.