Rate Law Lab

Written by Elijah Batchelder

Reaction Order and Rate Laws

03.24.2017

Lab Partner: Jackson Mendenhall

Lab Instructor: Nicole Capps
Introduction
In the following lab experiment, reactions will be induced in order to experimentally determine both the rate laws and the reaction orders of hydrochloric acid and sodium thiosulfate in the synthesis of the two solutions. A rate law is an equation which can tell you how fast a reaction will take place, dependent on the concentrations of each solution involved. A reaction order, usually described as either zeroth, first, or second order, gives the magnitude of variance when the concentration of a solution changes. This lab will cultivate a deeper understanding of these concepts, as well

They were given the labels of “HCl”, “Na2S2O3”, and “water”, as was done to the beakers. The “water” syringe was then used to extract 2 mL of water from the “water” beaker. The syringe was examined to verify that no air bubbles were made in the syringe. The water was then translated into Well #3. Next, the “HCl” syringe was used, taking 1 mL of HCl from the “HCl” beaker, and then translated into Well #3 as well. The same filling procedure above was used to fill the other wells, but with differing amounts of each solution. In Well #2, 1.5 mL of water and 1.5 mL of HCL was used. In Well #1, 0 mL of water and 3 mL of HCl was used. Once each well was filled, a stopwatch was prepared to time the reactions that would occur in the next steps. To begin the reactions, the “Na2S2O3” syringe was used to place 2 mL of Na2S2O3 into Well #1. As soon as the sodium thiosulfate was placed in the well, the stopwatch was started. The reaction was timed until the black “x” beneath the well was no longer visible. Once this point was reached, the timer was stopped and the time was recorded in Data Table #1. The same steps involving the addition of Na2S2O3 were repeated for Wells #2 and #3, using 2 mL of Na2S2O3 in each. The final times for each well was recorded in Data Table #1 in the appropriate blank. Once the first trial was completed for the first three experiments, a second trial was completed in Wells #4, #5, and #6 using the same procedure in order to increase accuracy. After each trial was conducted, each of the wells were emptied into the designated waste container and dried using a paper