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The obExperiment 1: Intro The objective of Experiment 1: Tools for Lab Measurement was to introduce how scientific knowledge is gained through careful observation and interpretation. Lab A: The Measurenet System's goal was to observe how temperature changes with time. This was accomplished by mixing ice in water with a temperature probe while the MeasureNet system automatically made, stored, and plotted the desired measurements. Lab B: Measurement of Mass and Volume's goal was to determine and compare the accuracy of different types of glassware while measuring mass and volume. This was achieved by determining the mass of water in the glassware on an analytical balance, then calculating the actual volume of the water, absolute error, and relative error of the different measurements. The concepts that relate to the lecture are absolute and relative error, temperature vs. time, and mass compared to volume and density. The lab techniques used were measuring temperature with a temperature probe, measuring volume with beakers, pipettes, burets, and graduated cylinders, and using MeasureNet to enter data using the table, temperature probe, and plot. Procedure The procedure followed was that given in the handout downloaded from Chemlabs21.com, Experiment 1: Tools for Lab Measurement. pp. 1-4 to 1-5 for part A and pp. 1-6 to 1-10 for part B. Error discussion The standard error for the beaker was 2.890 mL, 1.221 mL for the graduated cylinder, 0.210 mL for the pipet, and 0.233 for the buret. The standard deviations for the beaker and graduated cylinders should have been much closer to the buret and pipet than they were. Some possible errors with the experiment that might account for this include inaccurate measurements of the water in graduated cylinders and beakers involving an overestimate and underestimate of water, an inaccurate calculation of the mass and volume, or a failure to zero the analytical balance correctly. All of these errors would result in a standard deviation that is too high. Conclusion The objective of determining the temperature vs. time was achieved using a temperature probe and mixing water with ice until the temperature was constant, calibrating the probe, and using the MeasureNet system to plot the data. The temperature dropped significantly after the probe was calibrated. The objective of part B, finding the accuracy of specific types of glassware when measuring mass and volume, was achieved through measuring mass and volume of water, relative error, and absolute error of a beaker, graduated cylinder, pipet, and buret. The results showed a larger fault with accuracy in beakers and graduated cylinders which can be due to the experimental errors, discussed above.

Experiment 2: Intro The objective of experiment 2 was to determine the volume of NaOCl required to reach the stoichiometric point of the titration and calculating the number of moles of each reactant used at the stoichiometric point and determine the coefficients x and y. This was accomplished by placing a measured amount of a reducing agent in a beaker and adding an NaOCl solution of known concentration dropwise to the beaker until the reducing agent was completely consumed. By monitoring the temperature of the reaction, the stoichiometric point could be determined. The concepts involved are stoichiometry, molarity, and volume/concentration measurements. The lab techniques used were measuring volume with a buret, volumetric pipets, measuring temperature with a temperature probe, and using a drop counter.

Experimental procedure The procedure followed was that given in the handout downloaded from Chem21.com, Experiment 2: Reaction Stoichiometry by Thermometric Titration. pp 2-2 to 2-4. Error discussion: The calculated mole ratio for NaOCl/Ki was 2.5, NaOCl/Na2S2O3 was 1.3, NaOCl/Na2SO3 was 0.77, and NaOCl/KNCS was 3.7. There was no specific goal for the mole ratio but based on the results these ratios seem to be in line with the experiment. Some possible errors could have been reading the buret incorrectly getting the wrong NaOCl volume, reading the incorrect stoichiometric point on the volume mass graph, or overfilling/underfilling the 5 mL reducing agent. These errors could have resulted in an incorrect mole ratio but did not directly affect our experiment or results. Conclusion The objective of determining the volume of NaOCl required to reach the stoichiometric point of titration and calculating the number of moles of each reactant used at the stoichiometric point and determining the coefficients x and y was achieved by adding NaOCl drops into each of the four reducing agents until the stoichiometric point was reached on the graph. The mole ratios of each were determined and discussed in the error discussion. The ratios of each reducing agent makes sense due to the graphs of the stoichiometric point and any non-whole numbers can be attributed to the experimental error, discussed above.

Experiment 12 Error discussion The calculated V(tubing) value was ….. on the plot of pressure vs volume. The plot of pressure vs volume should have been essentially a straight line. This was achieved other than 1 outlier. The discrepancy could have been subject to many errors, To confirm gas behaves consistent with Amontons’ Law, the results of P(air)/T for each pair of data points should have been a relatively constant value for all points. The data for the pressure of air/ temperature ranged from 20 to 70. Some errors

Conclusion The objective of determining whether air behaves according to Boyle’s Law and Amontons’ Law was achieved by calculating V(tubing) and plotting a V(syringe) vs. 1/P(air) graph for Boyle’s Law and determining P(air)/T for Amontons’ Law. Once the information was graphed the values needed to determine if Boyle’s Law applied was seen in a straight line on the plot between the volume of the syringe vs. 1/ the pressure of air. Since the data acted in a straight line, the gas does behave according to Boyle’s Law. -5640 -4154...