Lab 3 / Reaction Order and Rate Laws

Purpose / IntroductionThis lab will provide a physically-observable demonstration of how concentrations will or will not affect reaction rates. The calculated reaction rates will then contribute to the determination of order for each reactant and the reaction's rate law.I expect the reactions between the reactants will produce a precipitate that will cloud the mixtures' visibilities. I also expect the time for the reaction rate will increase as the solution's dilution increases.

Materials and MethodsPart IData tables are set up to record the times obtained while observing the mixtures' physical changes. Initial and final concentrations of the varied compound are calculated.

Part IIThis part of the lab keeps the concentration of constant while the concentration is varied. The 24-well plate is placed on a sheet of white paper. Three as-close-to-identical black X signs are drawn below three of the wells. The well plate is then moved down to cover the X signs but remain visible under each well. Below this, each well is labeled 1, 2, and 3. Distilled water is added to wells 2 and 3. Next, a varying quantity of is added to each of the three wells. At the top of the three well columns is added. Using an empty pipet, suck up all the from the first well. Using a stopwatch, time the reaction that occurs when the is added to the first X well; keep the time running until the X sign is no longer visible. In the data table, record the length of time it takes for this result. Repeat this for wells 2 and 3. Once completed, the well plate should be washed with liquid soap and thoroughly cleaned. Repeat this part a second time to obtain a second set of data.

Part IIIThe third part of the lab mirrors that of the second part; however, the constant concentration is and the varied concentration is . The 24-well plate is once again placed on a sheet of white paper, and three black X signs are drawn below three wells. The well plate is moved to cover the X signs as before, and well is labeled 1, 2, and 3. Distilled water is added to wells 2 and 3. This time varied quantities of is added to the three wells. is added to the three top-column wells. Using a clean and empty pipet, all the is sucked up from the first well. The reactions between the nondiluted and diluted and is timed using a stopwatch; time is stopped when the X sign is no longer visible. Time is then recorded in the data table. Wells 2 and 3 will follow the same steps. Once completed, a second set of data is obtained after the well plate is thoroughly washed with liquid soap. Clean up the lab and surrounding area once all data has been obtained.

Part IVUsing the data obtained, calculations can be made to determine the rate laws.

SafetyFor this experiment goggles should be worn. Anything that comes in contact with the chemicals should be washed with liquid soap.