Preview of “Lab 11 PreLab - Redox Reactions”

Preview of “Lab 11 PreLab - Redox Reactions” - Lab 11...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 12/5/12 Lab 11 PreLab -‐‑ Redox Reactions Steve Yarush CH102, section 021, Fall 2012 Instructor: Brandon Zoellner WebAssign Lab 11 PreLab -­ Redox Reactions (Prelab) Current Score : 24 / 25 Due : Monday, November 12 2012 11:00 PM EST The due date for this assignment is past. Your work can be viewed below, but no changes can be made. Important! Before you view the answer key, decide whether or not you plan to request an extension. Your Instructor may not grant you an extension if you have viewed the answer key. Automatic extensions are not granted if you have viewed the answer key. Request Extension View Key 1. 8/8 points | Previous Answers NCSUGenChem102LabV1 11.PRE.01. Green checks and red X's are not displayed for this question. The following items deal with safety issues in the Redox Reactions lab. Select the correct response for each statement. (a) Choose the chemical in this experiment that has irritating vapors. all the oxidizing agents all the reducing agents KMnO4 3 M HCl (b) What should be done to avoid exposure to the vapors? Keep a damp cloth over the nose and mouth to capture the vapors. Work with it under a hood and avoid inhaling the vapors. Keep the container it is in closed at all times. Wear a dusk mask. (c) What produces hydrogen gas in this experiment? www.webassign.net/web/Student/Assignment-‐‑Responses/last?dep=4450491 1/7 12/5/12 Lab 11 PreLab -‐‑ Redox Reactions all the reducing agents KMnO4 both the oxidizing and reducing agents all the oxidizing agents (d) How should accidents be prevented when working with the reactions that produce hydrogen gas, which is flammable? Do not expose the reducing agents to water or acid. Do not work with the reactions in an atmosphere that contains nitrogen. Do not work with the reactions in an atmosphere that contains oxygen. Keep reactions away from ignition sources, and rinse metal before discarding it. (e) Select the chemicals in this experiment that are listed as acidic or corrosive. (Select all that apply.) 3 M HCl Zn(NO3)2 Pb(NO3)2 AgNO3 KMnO4 Cu(NO3)2 Mg(NO3)2 (f) If one of these solutions contacts the skin or clothing, what is the first thing you should do? www.webassign.net/web/Student/Assignment-‐‑Responses/last?dep=4450491 2/7 12/5/12 Lab 11 PreLab -‐‑ Redox Reactions Turn off all hotplates in the area to avoid igniting the spill. Neutralize the spill with a sodium bicarbonate solution. Notify the instructor about the accident. Flush the affected area with a lot of water. Redox Reactions 2. 4/5 points | Previous Answers NCSUGenChem102LabV1 11.PRE.02. The following questions deal with waste disposal from the Redox Reactions lab. (Select all that apply.) (a) What should be done with the wastes from Part A1 (Ranking Oxidizing Agents) of the experiment? The contents of the well plate should be rinsed into the labeled waste container. There will be no waste in this experiment. The waste solutions can be flushed down the sink. They should be put in the container for oxidizing agents. (b) What should be done with metal waste from Part A2 (Ranking Reducing Agents) of the experiment? Before disposal, the metal should be blotted on a paper towel to dry it. The metal should be placed in the container for waste metal. The metal can be thrown in a trash can in the lab. Before disposal, the metal should be rinsed with water if it has been in acid solution. The metal can be returned to the container from which it was taken. (c) What should be done with liquid waste from Part A2 (Ranking Reducing Agents) of the experiment? www.webassign.net/web/Student/Assignment-‐‑Responses/last?dep=4450491 3/7 12/5/12 Lab 11 PreLab -‐‑ Redox Reactions The liquid waste can go in the same container used for Part A. The liquid waste can be flushed down the sink with water. The liquid waste should go in the container for reducing agents. (d) Why should the container for the metals from Part A2 (Ranking Reducing Agents) not be tightly capped? Hydrogen gas could build pressure in it. Leaving the container vented will allow the metals to decompose. Leaving the container vented will allow heat from latent reactions to escape. (e) What should be done with the wastes from Part B (Half-­cell Potentials) of the experiment? The alligator clips should be clamped together and stored in the lab drawer. The filter paper may be thrown in the trashcan. The electrodes should be discarded in the proper jar. The metal wires should be rinsed and returned to the set-­up sheet to be used by the next lab section. The solutions should be rinsed into the waste container for redox solutions. Redox Reactions www.webassign.net/web/Student/Assignment-‐‑Responses/last?dep=4450491 4/7 12/5/12 Lab 11 PreLab -‐‑ Redox Reactions 3. 2/2 points | Previous Answers NCSUGenChem102LabV1 11.PRE.03. Green checks and red X's are not displayed for this question. The following questions refer to the procedures from Part A (Relative Reactivities) of the Redox Reactions lab. (Select all that apply.) (a) In Part A1, which oxidizing agents are to be reacted with KI (potassium iodide)? all of them the ones that did not react with H2O2 the ones that did react with H2O2 (b) In Part A2, which reducing agents are to be reacted with 3 M HCl? the ones that did react with water the ones that did not react with water all of them Redox Reactions www.webassign.net/web/Student/Assignment-‐‑Responses/last?dep=4450491 5/7 12/5/12 Lab 11 PreLab -‐‑ Redox Reactions 4. 5/5 points | Previous Answers NCSUGenChem102LabV1 11.PRE.04. Green checks and red X's are not displayed for this question. The following questions refer to the experimental procedures for Part B (Half-­cell Potentials) of the Redox Reactions lab. (Choose the best response for each item below.) (a) In what units will the meter initially report the reading? millivolts (mV) (b) To what units should this be converted? volts (V) (c) In what order should the readings be listed in Data Table B2? most negative to most positive (d) Which of the following equations correctly gives the cell potential? Ecathode = Ecell − Eanode Ecell = Eanode − Ecathode Ecell = Ecathode − Eanode Ecell = Ecathode + Eanode Redox Reactions www.webassign.net/web/Student/Assignment-‐‑Responses/last?dep=4450491 6/7 12/5/12 Lab 11 PreLab -‐‑ Redox Reactions 5. 5/5 points | Previous Answers NCSUGenChem102LabV1 11.PRE.05. Green checks and red X's are not displayed for this question. Check your ability to correctly define some of the terms associated with redox reactions. (a) A chemical species that gets reduced during a chemical reaction: loses electrons. gains electrons. (b) A chemical species that gets reduced during a chemical reaction: changes to a more negative oxidation state. changes to a more positive oxidation state. (c) A chemical species that gets reduced during a chemical reaction: is an oxidizing agent. is a reducing agent. (d) A chemical species that gets reduced during a chemical reaction: has a low-­energy unfilled orbital. has a high-­energy filled orbital. (e) A chemical species that gets reduced during a chemical reaction: obtains electrons from an oxidizing agent. obtains electrons from a reducing agent. Redox Reactions www.webassign.net/web/Student/Assignment-‐‑Responses/last?dep=4450491 7/7 ...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern