CHM 152ll
April 25, 2013
Some Factors that Affect the Rate of a Reaction
BACKGROUND:
Chemical reactions occur at different rates. In this experiment I will consider some of the key factors that influence the rate of a reaction: * nature of reactants - particle size * temperature * catalysts According to the collision theory, the rate of a reaction depends on the frequency of collisions between reacting particles. The more frequent the collisions, the faster the rate of the reaction. However, in order for the collisions to be effective, the particles must collide with sufficient energy (activation energy). Furthermore, the particles must collide with the proper orientation.
The factors that will be examined in this lab influence reaction rate by either increasing how often collisions occur or by making collisions more effective.
PURPOSE: To explore the effects of temperature, surface area, and a catalyst on the rate of a reaction.
HYPOTHESIS:
1. If the rate at which the Alka Seltzer tablet dissolves is related to the temperature, then the temperature will affect the rate at which the tablet dissolves.
2. If the rate at which the Alka Seltzer tablet dissolves is related to the surface area, then the surface area will affect the rate at which the Alka Seltzer tablet dissolves.
3. If the rate at which Alka Seltzer tablet dissolves is related to the catalyst, then the catalyst will affect the rate at which the tablet dissolves.
MATERIALS: Thermometer, 250mL Beakers(3), Mortar and pestle, Alka-Seltzer tablets, Timer with a second hand, Ice Water, Microwave, Vinegar (acetic acid), Table salt.
PROCEDURE:
Part 1: Affects of Temperature
1. Prepare three beakers half-full of water at three different temperatures. * Half-fill the first beaker with ice water. * Half-fill the second beaker with tap water and allow it to set to reach room temperature. * Pour half 250mL beaker amount of tap water into
References: Theodore L. Brown, H. Eugene LeMay, Jr.,Bruce E. Bursten, Catherine J. Murphy, Patrick Woodward. (2007). Chemistry: The Central Science (11th ed.). Upper Saddle River: Pearson Prentice Hall.