experiment 23 pre laboratory assignment

Order ready-to-submit essays — 100% plagiarism-free guaranteed!

Note: Our papers are 100% human-written. 

Experiment 23 – Factors Affecting Reaction Rate General Chemistry I Lab 1112.55

The University of Texas Rio Grande Valley

Professor Name

 Student Name

Partner’s Name: Cynthia Garcia

Experiment Date

Objective

During this experiment, the student will investigate and compare the different factors that influence the rate of reaction of some chemicals.

Introduction

The student will be taught the term chemical kinetics, where the studies are done on the reaction rates, how the reaction rates can be controlled, and the pathway or mechanism that the reaction takes from the reactant to the product. Fortunately, the reaction rates may either change to either very fast or very slow. This can typically be given as a change in the concentration of a reactant. As the increase in the concentration increases, the faster the rate of reaction becomes.

They are the other frameworks that can be used to change the concentration of a chemical reaction. An example is to observe the change of the chemical reaction by changing the color, temperature, and pH, the evolution of gases, odour, and the conductivity of the chemical reaction.

In this experiment, the student will investigate “four out of five factors” that can affect the reaction rates. They are: nature of reactants, temperature of the chemical system, presence of catalysts, and concentration of the reactions (exception: surface area of the reaction). The changes to some chemicals may happen quite fast due to the peculiarity of these chemicals to be more reactive.

In addition, a 10 C increase in temperature doubles the speed of the chemical reaction. The excess heat not only raises the number of collisions between the molecules of the reactant but also increases the kinetic energy. The presence of catalysts can be seen when the pathway of the chemical reaction reroutes so that the “alternate” path has a lower activation energy than the unanalyzed reaction. The increase in the concentration of reactants increases the reaction rate. So, the greater the concentration of molecules of the reactant enhances the odds of an effective collision of the reacting molecules will occur in the creation of the product.

Procedures

1. Nature of the Reactants

1. The various acids influence the rates of reaction.
   1. Half-fill a set of four labeled small test tubes with 3M H₂SO₄, 6M HCl, 6

CH₃COOH, and 6M H₃PO₄

1. In each test tube, put a 1-cm strip of magnesium ribbon.
2. Compare the rate of reaction and note down your observations.

2. Reaction rates are influenced by different metals.
   1. Weighing 6M HCl, fill a set of three labeled small test tubes half-full.
   2. Wet 1-cm pieces of zinc, magnesium, and copper one at a time.

into the test tubes.

1. Compare the rates of reaction of each metal with HCl.

1. Temperature of the Reaction: Hydrochloric Acid–Sodium Thiosulfate Reaction System

1. Prepare the solutions

. Add 2 mL of 0.1M Na2S2O3 into three 150-mm tubes of a set of three.

1. Second group of three test tubes with 150 mm in length.
2. Pipet 2 mL of 0.1M HCl
3. Label the sets of test tubes.
4. The first pair of Na2S2O3–HCl pair test tubes is to be combined at room temperature. Part B. 2
5. Put the second pair of Na2S2O3HCl pair test tubes in an ice water bath or Part B.3
6. Adding to a warm water bath: A third pair of Na2S2O3HCl test tubes. (<60°C) for Part B.4
7. Wait until each pair of test tubes has achieved thermal equilibrium (~5). minutes) before continuing to Parts B.3 and 4

2. Record the time for reaction at room
   1. Make sure that you are ready to begin time on keeping track of the reaction rate.
   2. Combine the first pair of Na₂S₂O₃–HCl pair test tubes
   3. START TIME
   4. Shake the mixture for a few seconds.
   5. STOP TIME when the translucidity of the sulfur shows.

1. Note the time interval and temperature of the room, with all of the definite digits along with the less-than sign.

3. Record the time for reaction at the lower temperature
   1. From the ice bath, pour the HCl solution into the Na₂S₂O₃ solution
   2. START TIME
   3. Shake the mixture for a few seconds.
   4. Add the reaction mixture to the ice bath.
   5. Stop time at which the murkiness of the sulfur is manifested.
   6. Note the difference in time between the reaction and the temperature of the bath, with all assured digits as well as one of the uncertain digits.

4. Record the time for reaction at the higher temperature
   1. Add the solution of HCl to the solution of Na2S2O3 in case of the warm water bath.
   2. Proceed as in Parts 2 and B.3.
   3. Record the appropriate
   4. Repeat any of the aforementioned reactions as it is considered necessary.

5. Plot the
   1. Plot temperature (y-axis) versus time (x-axis) using appropriate software
   2. Give an interpretation of your data according to the suggestions on the Report Sheet.

C. SKIP PART C

1. Presence of Catalysts
   1. Add a catalyst
      2. Add to a clean small test tube about 2mL of a 3 percent H2O2.
      3. To the solution, add 1 or 2 crystals of MnO2.
      4. Observe
      5. Note its instability

E. SKIP PART E

1. Concentration of Reactants: Iodic Acid-Sulfurous Acid
   1. Prepare the test solutions
      23. See the making of the test solutions in Table 23.1.
      24. Prepare a test tube rack, 5 clean and labelled test tubes.
      25. Determine the volumes of the 0.01M HIO3, starch, and water using the dropping technique.
      26. Measure the volume (mL) of the HIO3 dropping pipette by measuring the drop volume at different HCl concentrations.
      27. Measure a second dropping (or Beral) pipette with water to measure them L per drop.
      28. Calibrate the third dropping (or Beral) pipette of the 0.01M H2SO3 solution, which delivers 1 mL.
      29. Indicate the level on the pipette such that 1 mL of the can be delivered quickly.
      30. An H2SO3 solution can be made for each test tube
      31. Alternatively, apply a 1-mL Beral pipette that is calibrated.

2. Note the time for the
   1. Get a piece of white paper and put it next to the test tube.
   2. As one student quickly transfers 0 mL of the 0.01M H₂SO₃ to the respective test tube
   3. The other notes the time
   4. Immediately agitate the test tube
   5. Note the time lapse (seconds) for the deep-blue I3 •starch complex to

Appear

3. Complete remaining solutions
   23. . Repeat Part F.2 with the rest of the reaction mixtures in Table 23.1.
   24. Repeat any trials if necessary

4. Plot of the data
   1. With the help of the suitable programs, plot each solution, the initial concentration of iodic acid [HIO3]0 (y-axis), versus the time in seconds (x-axis) of the reaction.

Data Sheet

A. Nature of the Reactants
List the acids in order of decreasing reaction rate with magnesium	HCl, H2SO4, CH3COOH, H3PO4
List the metals in order of decreasing reaction rate, 6M HCl	Mg, Zn, Cu
Identify the metals reacting in Figure 23.5 (from left to right)	Mg, Cu, Zn

Calculations

Results/Discussion

I think in this experiment, my results were very good. I believe that the experimentation procedures were adhered to and addressed properly. Therefore, the experiment was very successful. The only exception that it is likely to have is Part F., which is the concentration of reactants. The outcome of that section of the experiment may be inaccurate due to the possibility of the drops being counted incorrectly, or the calculations may be wrong. On the other hand, the rest of the experiment was produced successfully.

Conclusion

The aim of the experiment was achieved and documented. I learned in this experiment how to find the factors that affect the reaction rates by using the four or five factors: nature of the reactants, temperature of the chemical system, presence of a catalyst, and concentration of the reactants. By observing these factors, I could also observe how the dependence on one factor or the other factor (temperature of the chemical system) depended on which factor was used.

Laboratory Questions

1. Why does the reaction rate of virtually all reactions increase with an increase in temperature? Assuming you were to prepare a glass of sweetened iced tea the old-fashioned way, i.e., by adding sugar and ice cubes to a glass of hot tea, what would you add first?

2. One hundred and forty drops of DI water, one drop of starch solution, and 1.0 mL volume of H2SO3 will be added to the mixture of these components. Supposing that all solutions have a drop, per mL, the initial molar concentration of [HIO3].

3. Reaction of Mg with HCl produces hydrogen gas, as we saw in class. Provide a prediction of the gas generated during the reaction of calcium carbonate with HCl and write the balanced equation of the reaction.

4. In which case of the reactions with the given amounts of Mg, which acid is going to react more slowly, or will they both have the same reaction rate? Explain.

5. How does a catalyst work?
   1. It speeds the reaction by increasing the temperature of the reaction.
   2. It causes the reaction to be faster because it raises the concentration of the reactants.
   3. It accelerates the reaction by reducing the activation energy of the reaction.
   4. It accelerates the reaction since it is used up in the reaction.