What are the identities of the substances found after electrolysis and heating? The identities of the substances found were Iodine, Iodide ion (I-), Triodide ion(I3-), Zinc metal and Zinc ion(Zn2+) Post Lab questions: 1. What did this experiment convincingly show about the composition of the white solid? I put that the experiment showed us the white substance was comprised of Zinc ions and iodide ions, and that the two ions and be separated back into their respective elements 2. During the electrolysis, a gray solid formed on the negative wire of the battery and the dark red solution formed at the positive wire of the batter.
Focus Question Should chemists prepare Zinc Iodide, from its elements or from a Double Replacement Reaction between Barium Iodide and Zinc Sulfate? -To put things into perspective in terms of cost efficiency, zinc granules cost about $62.50 per kilogram or $.0625 per gram. Also, Iodine chips cost about $.1498, Barium Iodide Dihydrate costs about $.886 per gram, and Zinc Sulfate Heptahydrate costs about $.0405 per gram. According the chemical reaction listed below, the double replacement reaction creates a solid Barium Sulfate precipitate This means that the ZnI2 is less pure than it would be from just the Zinc and the Iodine. With the elemental reaction you get ZnI2 as your only product thus indicated that it is “pure” Zinc Iodide.
| Centrifuge: used to isolate the solid from the solution | . Focus Questions: When acidified water is not used in the zinc and iodine synthesis, zinc hydroxide is formed. How can it be identified based on the amphoteric nature. When zinc and iodine react without the presence of acetic acid in the water, zinc hydroxide forms. This is evident because the substance tested positive for both the acid test and the base test for zinc hydroxide.
The purpose of the lab was to determine which reactant was the limiting reactant, and to see how much of the other reactant was used. The true molarity of a compound can be defined as the amount of moles per liter of that substance. The equation of this single displacement chemical reaction done during this lab is 2Al(s) + 3CuCl(aq) → 3Cu (s) + 2AlCl2 (aq). In the reaction, the solid Aluminum replaces the Copper in Copper (II) Chloride to produce solid copper, and Aluminum Chloride. In order to find which reactant is the limiting reactant, an equation based on the molarity of the Copper (II) Chloride may be used, or the products of the reaction may be observed.
Halides Lab: Background information: Halide ions are reactive and useful. Salts are positively charged ions (metals) combined with any negative ions (nonmetal), and when placed in a solution (water) it separates into the cations and anions that made it up. The Purpose of this lab is to find out how the Halides react with the indicators, and to determine the identity of the two unknown solutions (A and B). Color of solutions prior to experiment: NaF | NaCI | KBr | KI | Unknown A | Unknown B | clear | clear | clear | clear | clear | clear | Color of indicator prior to experiment: 5% Bleach (NaOCI) | 0.2 M Na2S2O3 | 0.1 M AgNO3 | 0.5 M Ca(NO3)2 | clear | clear | clear | clear | Halide solutions | NaF | NaCI | KBr | KI | unknown A | unknown B | Test 1: Ca(NO3)2 | Cloudy White (Nothing) | Clear | Nothing | light yellow (Nothing) | Nothing | Nothing | Test 2, Part A: AgNO3 | clear (Nothing) | Milky White | Gold (Cloudy yellow) | milky green (Cloudy yellow) | turned white, film developed on top layer | Milky | Test 2, Part B: add Na2S2O3 to test tube from part A | Dark Orange/brown | Clear | Dark Gold(precipitate yellow then clear) | milky green (no change) | white precipitation, settled on bottom | Milky | Test 3: NaOCI (Bleach) | Clear (Nothing) | Nothing | Nothing | Orange (Clear) | Nothing | Orange | Unknown A is identified as NaCI (Sodium Chloride), because in test#1 the solution turned a cloudy white color when Ca(NO3)2 (Calcium nitrate) was added. In the first part of test#2, when AgNO3 (Silver nitrate) is added, the solution turned white, with a thin layer of film developing on the surface.
c) If the percentage yield is 85.0%, what mass of precipitate is actually produced? d) How many moles of silver ions remain in solution? e) What is the concentration (M) of potassium ions that remain in solution? Problem 2 Ethanol (C2H5OH) reacts with permanganate ions in acidic solution to produce acetic acid and manganese (II) ions. Since this reaction involves a dramatic color change, it can be used in a titration experiment.
Create a data table similar to the one below named Data Table: Oxidation-Reduction Experiment. 2. Take a 24-well plate: a. In well A1: Place 10 drops of Sodium Sulfate, Na2SO4 b. In well A2: Place 10 drops of Magnesium Sulfate, MgSO4 c. In well A3: Place 10 drops of Zinc Nitrate, Zn(NO3)2 d. In well A4: Place 10 drops of Iron (III) Chloride, FeCl3 e. In well A5: Place 10 drops of Copper (II) Sulfate, CuSO4 3.
For example, if you mix aqueous solutions of AgNO3 and NaCl, there are two new combinations of ions possible. The silver nitrate solution contains Ag+(aq) and NO3-(aq). The sodium chloride contains Na+(aq) and Cl-(aq). Possible new combinations of these ions are AgCl and NaNO3. Note: these formulas would have been written in the upper right hand corner of each box before beginning the lab.
palladium on carbon 13 of 22 4/16/12 9:15 PM StudyBlue Flashcard Printing of Lab Final 2211L UGA http://www.studyblue.com/servlet/printFlashcardDeck?deckId=... Which alkyl halide would react fastest in a nucleophilic substitution using silver nitrate in ethanol? 3-bromo3-methylpentane bc its sn1 Which alkyl halide would react fastest in a nucleophilic substitution using sodium iodide in acetone? 1-bromopentane bc its sn2 What is the name of the chemical reagent used as the source of Br2 in the preparation of diphenylacetylene? pyridinium hydrobromide perbromide type of stationary phase column length column temperature rate flow of the carrier gas List the 4 general factors that affect the separation obtained on a gas chromatograph What specific technique is used to collect/isolate your purified unknown compound at the end of the recrystallization experiment?
Kumari Biswas Chem 106 – 07 October 06, 2014 Menglu Shi Group member: Shemeika McLaren, Jose Suarez, Colleen Shum Lab 3: Redox Arena Redox Arena Lab Part I Observations and Data Observations of starting materials and standards Chemicals | Observations | The Four standards | Granular zinc | Silver-gray irregular solids | Iodine crystals | Purple-black spherical solids, strong smell | Zinc ion and iodine-iodide-triiodide ion in H2O | Red brown liquid | Zinc iodide | Gray white solid powder | Chemicals used for tests | 0.17 M acetic acid | Clear liquid | Mineral oil | Thick clear liquid | Silver nitrate (AgNO3) | Clear liquid | Magnesium turnings | Solid curled metals | 3 M HCl | Clear liquid | Other chemicals