The purpose of this experiment is to determine how the variation of concentration has an affect on the rate of a chemical reaction. In this experiment we will be taking a look at the reaction between magnesium and hydrochloric acid, and determine the rate law for this particular reaction. The term rate is defined as the change of concentration over the change in time and is represented algebraically as: Rate = k [A]x[B]y , with k being the rate constant, A and B being the concentration of the reactant to the x and y order. In this experiment we will be looking as the change of concentration of magnesium over the change in time. There fore the formula for rate is written as: Rate = k [HCl]y. Through graphing the data obtained in this experiemtn we will be able to determine the order of the reaction and the rate constant, k.
The first step is to prepare the solute by measuring a series of magnesium strips to approximately the same length to be used for all of our reactions. Our goal was to measure and cut 1.5 cm of a magnesium strip. The next step was to prepare the solvent in several dilutions, which would yield different concentrations. The solvent used was hydrochloric acid 2.0 M, diluted with deionized water, and the desired concentrations were 2.0 M, 1.5 M, 1.0 M, 0.75 M, and 0.5 M. The concentrations were prepared in advance, a strip of magnesium was introduced to the concentration contained in the beaker, and it was gently swirled while the time was being recorded until the magnesium strip disappeared. The reaction time was recorded with the temperature of the solution after the reaction.
3. Table I Reaction Data
Reaction I II III IV V
Length of Mg Strip 1.6 cm 1.5 cm 1.5 cm 1.5 cm 1.6 cm
Mass of Mg .019 g .018 g .018 g .018 g .019 g
Volume of HCl 25.0 ml 18.75 ml 12.5 ml 9.4 ml 6.25 ml
Volume of Distilled H2O 0.0 ml 6.25 ml 12.5 ml 15.6 ml 18.75 ml
Concentration of HCl 2.0 M 1.5 M 1.0 M 0.75 M...