In an experiment, one plastic cup is filled with cold water and another cup is filled with hot water. One antacid tablet is dropped into each cup. Which cup has the faster reaction? Why is the reaction faster in that cup?

Answer 1

In the described experiment, the cup with hot water will have the faster reaction when the antacid tablet is dropped into it.

The reason for this is that an increase in temperature generally increases the rate of a chemical reaction. Here’s why:

1. Increased Molecular Movement: In hot water, the molecules move faster due to the higher energy levels. This increased movement leads to more frequent collisions between the reactant molecules (in this case, the antacid tablet and water) which is fundamental for reactions to occur.

2. Higher Reaction Rate: According to the collision theory of chemical reactions, a greater number of collisions per unit time leads to an increased likelihood of effective collisions (collisions that result in a reaction). Since the hot water provides more energetic collisions, this results in a quicker disintegration of the antacid tablet, leading to the faster production of carbon dioxide gas (a common result of the reaction between antacids and water).

3. Solubility: Higher temperatures typically increase the solubility of solutes in liquids, which means the components of the antacid may dissolve more readily in hot water than in cold water.

In summary, the reaction in the hot water cup will occur faster due to increased molecular motion, higher collision rates, and potentially better solubility, leading to a more rapid breakdown of the antacid tablet.