Reaction Order and Rate Laws Purpose: Students study the effect Of reactant concentration on the rate Of the reaction between sodium tessellate and hydrochloric acid. The order of each reactant and the rate law for the reaction is determined. Procedure: Before beginning: Set up data tables similar to the two data tables given. Making sure to fill in the needed columns. Part 1: 1. Place the 24. Well plate on a piece of white paper and draw threw equally thick black Ax’s beneath each of the lower threw left wells, Then move the plate to here the lower three left wells are above the Xx.
Make sure you can see the Xx clearly through the wells, On your paper label the wells l, 2, and 3 below each well. 2. Add 6 drops of distilled water to well #D-2 and 8 drops of distilled water to well *D-3 3. From the HCI bottle add 12 drops to well #1; 6 drops to well and 4 drops to well #3. 4. In the top three left wells add 8 drops of Nauseas _5_ Label a pipette Nauseas and carefully pipette out the contents in well *A-I and add it to well #1 and immediately begin timing with your stopwatch. Steps 2-5 included 6. Observe well #1 While a reaction occurs, and Stop the stopwatch When you can no longer see the X on the paper below the well. 7. Repeat Steps 5 and 6 for well #2 and well #3 and record the data in the correct columns in Table 1. 8. Immediately wash the wells with liquid soap and thoroughly dry the plate to prevent precipitates from forming at the bottom at the well. 9. Obtain a second set of data by repeating all the above steps and record the data in table 1 under trial 2. Part 2: l.
Place the 24-well plate on a piece of white paper and draw threw equally thick lack Ax’s beneath each to the lower threw left wells. Then move the plate to where the lower three left wells are above the Xx, Make sure you can see the Xx clearly through the wells. On your paper label the wells 1, 2, and 3 below each well, 2 Add 6 drops of distilled water to well #D-2 and 8 drops of distilled water to well #D-3 3. From the Nauseas bottle add 12 drops to well #1; 6 drops to well #2; and 4 drops to well 4 In the top three left wells add 8 drops of HCI 5.
Label a second pipette HCI and carefully pipette out the contents in well #A-I and ad it to well #1 and immediately begin timing with your stopwatch. [I Steps 1-5 are included 6. Observe well #1 while a reaction occurs, and stop the stopwatch when you can 7. Repeat steps 5 and 6 for well #2 and well #3 and record the data in the the well. 9. Obtain a second set to data by repeating all the above steps and Data Tables: Table 1: Varying the Concentration of 1. 0 M HCI Table 2: Varying the Concentration of 0. 3 M Nauseas Observations: Each of the reactions looked similar to each other.
The contents in the well slowly to cloudy and began to turn a white color, After some short time the reaction turned to a solid color that was slightly gray and the X was no longer seen. When the reaction sat for long enough it turned yellow, and continued to get darker the longer it sat. Each reaction slowly increased in time with the first the shortest amount of time and the third the longest amount of time. Questions: A. Calculate the initial and final concentrations as needed to complete Tables I and 2 Shown in Table 1 and 2 B.
Calculate the average reaction time for each reaction by adding the time for he two trials and dividing by 2. Shown in Table 1 and 2 C. Calculate the reaction rate by taking the inverse of the average reaction time, i. E. , I divided by the average reaction time. A. Else table I to determine the reaction order for HCI Reaction order = O b. Use table 2 to determine the reaction order for Nauseas Reaction order = 1 D. Write the rate law for the reaction Rate k[Nauseas] E. Using the rate law, the rate, and the appropriate concentration(s) from one (or more) of your experiments calculate k. . 03 = key. 18] k-O. 67 sec-I F. What are the potential errors in this experiment? Potential errors in the experiment would mostly be human errors. Different people may be able to see the X longer than the next person. Human error can also occur in reaction time for how quickly the stopwatch was pressed. Different data can also lead to different k values as the reaction rate could vary. The values for the reaction order were not nice whole numbers so they could be a contributing factor to getting the wrong k value, that could vary between experiments.