Lab 4: Understanding Oxidizing Strengths in Redox Reactions

LAB 4 –UNDERSTANDING OXIDIZING STRENGTHS IN REDOX REACTIONS– LAB REPORT C H M 2 0 4 5 L - D r. Y a v u z P e t r o w s k i The statement is: “I cer fy that this is my own work and I understand that if I am found to be in viola on of the honor code, I will be subject to the highest penalty”. INITIAL: JC Jetzebell Callens z23744291 PRELAB: Background: Please complete the following sec ons. Purpose of the experiment: In your own words, the purpose of the experiment including a brief descrip on of the lab and the reason for doing the experiment (what we are trying to determine and how we will go about determining it). Explain the concepts we are inves ga ng; explain why and how they are useful, how those concepts apply to the experiment; show relevant equa ons if you need to. The goal of this experiment was to introduce students to redox reac ons. Various chemical combina ons were mixed to observe whether a redox reac on took place. If a reac on occurred, the students were tasked with iden fying the process and explaining the reasons behind that par cular reac on. ti ti fl fl ti ti ti fl ti tt ti ti ti ti fl fl fl tt ti ti ti ti ti Flow Chart: Complete experimental procedure for this experiment by using informa on provided in the power point and 360 experimental video in a ow diagram format. A ow chart indicates the procedure of how experiment is performed. The ow chart must be wri en in the correct ow chart format (box and arrow). Handwri en ow charts are not accepted. See the example of the ow chart in canvas module. Chemicals Safety Hazard HNO3 eye, throat, respiratory and skin irritation. NaHSO3 corrosive to skin or eyes. If inhaled can cause severe irrita on to nose and throat. NaOCI skin and eye irrita on. Also is corrosive to certain metals. FeCl3 Corrosive and can cause severe irrita on to skin and eyes if contact is made. KI Slight eye and skin irrita on. Most hazardous if ingested or inhaled. KBr In high concentra on, potassium bromidestrongly irritates the gastric mucous membrane,causing nausea and some mes vomi ng. HCl Highly corrosive. Can cause burns and can also react with metals to form a ammable hydrogen gas. KMnO4 Can cause skin and eye irrita on. Also, is ammable. DATA ANALYSIS Handwri en lab reports are not accepted SYSTEM #1: 2FeCl3 + 2KI  2FeCl2 + 2KCl + I2 1. For System 1 reac on, record your observa ons below. ti ti ti ti fl ti ti ti ti ti ti tt When starch was added to the solution, the color changed to what appeared to be either dark blue or black. ti fl Waste Collec on: Type out the chemicals used in this experiment, and their hazards if applicable, and any other safety concerns associated with this experiment. You can search for the Materials Safety Data Sheet document on the internet to list hazards and safety concerns. You can add an extra row if you need extra space. 2. Did a redox reac on occur? Explain what your observa ons indicate about the redox reac on. If a reac on occurred complete ques ons 3-7. Yes, a redox reac on did occur. When the starch was added the color changed, this tells us that I2 was formed which indicates that a redox reac on did occur. 3. Which atom is oxidized, and what are its ini al and nal oxida on numbers? Iodine was oxidized since its oxidation state increased from -1 to 0. Initial state = -1Final state = 0 4. Which atom is reduced, and what are its ini al and nal oxida on numbers? Iron (Fe) is what is reduced because its oxidation state decreases. Initial state = +3 Final state = +2 5. Write the half equa on for the oxida on reac on. KI^-1(aq) --> I2^0(aq) + e- 6. Write the half equa on for the reduc on reac on. FeCl3^+3 + e --> FeCl2^+2 7. What other ions are in solu on, and what are their roles? Other ions in the solution are K+ and Cl-. They are there to neutralize the electrical conductivity. 2MnO4 - + H + + 5HSO3 -  2Mn 2+ + 5 SO4 2- +3H2O SYSTEM 2: 8. Record your observa ons below. ti ti ti ti ti fi fi ti ti ti ti ti ti ti ti ti ti ti ti ti ti fi At rst the solution is a purple color. After the reaction is complete the solution turned clear. 9. Did a redox reac on occur? Explain what your observa ons indicate about the redox reac on. If a reac on occurred complete ques ons 10-16. Yes, redox reaction occurred. Since there was a change in color to the solution, we know a reaction occurred. 10. Which atom is oxidized, and what are its ini al and nal oxida on numbers? Sulphur is oxidized. Initial oxidation = +4 Final oxidation = +6 11. Which atom is reduced, and what are its ini al and nal oxida on numbers? Manganese is reduced from left to right.Initial = +7Final = +2 12. Which substance (not atom) is being oxidized? HSO- is oxidized. 13. Which substance (not atom) is being reduced? MnO- is reduced. 14. Write the half equa on for the oxida on reac on. 5HSO3 --> 5SO4^-2 15. Write the half equa on for the reduc on reac on. 2MnO4^- --> 2Mn^2+ 16. A er the reac on is complete, what other ions are in solu on and what are their roles? H^+ which acts as an acidic medium for balance. OCl - + 2Br - + H2O  Cl - + Br2 + 2OH- SYSTEM 3: 17. Record your observa ons below. ti ti ti ti ti ti fi fi ti ti ti ti ti ti ti ti ti ti ti ti ft The solution changed colors, from clear to a yellow color. 18. Based on your observa ons, did a redox reac on occur? Explain what your observa ons indicate about the redox reac on. If a reac on occurred complete ques ons 19-25. The solution changed to a yellow color due to the addition of Br2 which tells us a reaction did occur. 19. Which atom is oxidized, and what are its ini al and nal oxida on numbers? Br is oxidized.Initial = -1Final =0 20. Which atom is reduced, and what are its ini al and nal oxida on numbers? Cl is reduced.Initial = +1Final = -1 21. Which substance (not atom) is being oxidized? Br- is being oxidized. 22. Which substance (not atom) is being reduced? OCl- is being reduced. 23. Write the half equa on for the oxida on reac on. 2Br-(aq)-->Br2 (aq) + 2e- 24. Write the half equa on for the reduc on reac on. OCl-(aq) + H2O (l) + 2e-->Cl-(aq) + 2OH-(aq) 25. What other ions are in solu on and what are their roles? OH- which balances the H and O in the equation. SYSTEM 4: Reac on of acids with metals 26. Is there any chemical reac on between Zinc metal or powder and 1.0 M HCl? If there is, write ti ti ti ti fi fi ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti ti balanced chemical equa on for these reac ons. Zn(s) + 2HCl(aq)-->ZnCl2+ H2(g) 27. Record your observa ons for the reac on of zinc metal and acid below. When one is added to the other it starts to form bubbles as gas is released. 28. Record your observa ons for the reac on of copper metal and acid below. There was no observable reac on that occurred. CONSIDERATION FOR DISCUSSION & CONCLUSION As you write your discussion and conclusion paragraphs for the discussion assay, here are some ps and ques ons you should answer. These are in addi on to the "Guidelines for a good discussion and conclusion" document in the introduc on module. • List ve types of chemical reac ons. What is the proof of chemical reac ons? Explain according to the experimental results. Be speci c. • What are the common proper es of oxida on and reduc on reac ons? • Explain one of the systems in which you observed oxida on and reduc on reac ons. How did you determine if it is an oxida on and reduc on reac on? • What are spectator ions? Did you include your spectator ions in molecular and complete ionic equa ons? In which cases where spectator ions are not included in chemical equa ons? • In system 4. did both metals react with HCl? If it did not explain the reason. DISCUSSION & CONCLUSION ASSAY ti ti ti ti ti ti ti ti ti ti ti ti ti ti fi ti ti ti ti ti ti ti ti ti fi In this experiment, we investigated various types of chemical reactions, focusing primarily on redox reactions. We identified several key indicators of these reactions, such as color changes and gas production, which provided evidence of chemical transformations. The common properties of oxidation and reduction, including electron transfer and changes in oxidation states, were clearly observed. In one system, we tracked electron movement to confirm that a redox reaction was occurring. We also discussed the role of spectator ions, noting that while they were included in complete ionic equations, they were excluded from net ionic equations since they do not participate in the reaction. Additionally, in System 4, we found that not all metals reacted with hydrochloric acid (HCl), which can be attributed to differences in their reactivity. Overall, this experiment enhanced our understanding of chemical reactions and the principles of redox processes.