The document describes an experiment to investigate factors that affect reaction rates. Students crush one antacid tablet to increase its surface area and observe it dissolving faster than an uncrushed tablet in water. They also heat one beaker of water and observe the antacid tablet dissolving faster in hot water than cold water due to increased molecular motion at higher temperatures. Finally, the teacher demonstrates how higher concentrations of reactants lead to faster reaction rates.

1. Introduction to Reaction Rates – Acivity
Part 1 – Surface area
Define surface area –
1. Fill both beakers with water.
2. Crush ONE antacid tablet using mortar and pestle.
3. Open another antacid tablet, but do not crush – set aside.
4. Once the first antacid tablet is crushed, simultaneously drop the whole antacid
into one beaker of water and the crushed antacid into the second beaker of water.
Stir both if desired.
5. After one has completely dissolved, dispose of the water solutions (remove any
leftover parts of antacid and throw this away – do NOT throw down the sink)!
Which one dissolved first? Why do you think this was the case?
Part 2 – Temperature
What happens to the speed of molecules as the temperature increases?
1. Refill both beakers with water.
2. Turn the hot plate on to about 4000 and place one beaker on the hot plate.
3. Allow it to warm for about 5 minutes.
4. Remove two antacid tablets from wrapper. Drop into each beaker (cold and hot)
one full antacid tablet. Stir if desired.
5. After one has completely dissolved, dispose of the water solutions (remove any
leftover parts of antacid and throw this away – do NOT throw down the sink)!
Which one dissolved first? Why do you think this was the case?
Part 3 – Concentration
Teacher Demo