White precipitate shows the presence of chloride (Cl-). Chloride anion equation: HCl(aq) + AgNO3 (aq) → HNO3 (aq) + AgCl(s). The nitrate anion test involves cooling a mixture containing 1 mL of test solution and 3mL 18M H2SO4. 2mL is poured down the inner test tube side and the presence of a brown ring shows nitrate (NO3-) to be present. The carbonate anion test mixes 1 mL of test solution and drops of 6M HCl.
Repeat the titration until there are two titres within 0.1cm3 of each other. Record results in a suitable table. Results: Rough Titre: 7.653 First Run: 6.553 Second Run: 6.453 Third Run: 6.553 Calculations: During the titration, iron(II) ions are oxidised to iron(III) ions and manganate(VII) ions are reduced to manganese(II) ions. The equation is as follows: 5Fe2+(aq) + MnO4-(aq) + 8H+(aq) ? 5Fe3+(aq) + Mn2+(aq) + 4H2O(l) The above equation shows that one mole of manganate(VII) ions reacts with 5 moles of iron(II) ions in acid solution.
HCI and blue dye. Blue dye and NaOCl (sodium hypochlorite). Observe, then add 1 drop of HCl. KI (potassium iodide) and Pb(NO3)2 (lead nitrate). Describe the precipitate formed.
After a small amount of time the solution began to produce gas and the copper was being used up in the reaction. The solution turned an aqua like blue and eventually all of the copper had now been used into this blue solution which was copper nitrate and water, the gas being produced was nitrogen dioxide and the fume hood had removed it during the reaction. Next we slowly added drops of 6 molar sodium hydroxide to the solution until it became basic and turned a red piece of litmus paper blue. While we added NaOH the solution turned green indicating a new reaction had occurred and turned the litmus paper blue. We then began to heat and stir the solution until it changed color again and it turned black with a layer of water on top.
| Observations of Chemicals | Zinc Sulfate | Powder of a white solid | Barium Iodide | Powder of a white solid. | Deionized water | Liquid, transparent. | Trial # | BaI2 | ZnSO4 | Theoretical Yield of ZnI2 | Actual Yield | Percent Yield | 1 | .67g | .45g | .499820g | .52g | 104% | 2 | .67g | .45g | .499820g | .52g | 104% | 3 | .66g | .46g | .493117g | .48g | 97% | Calculations for Cost | Double Replacement | Synthesis | 0.48 grams of Zinc Sulfate - $0.02 | 1.00 gram Granular Zinc - $62.50 | 0.67grams of Barium Iodine Dihydrate - $0.886 | 2.00 gram Iodine - ($74.90 × 2) - $149.80 | 0.52 grams of Zinc Iodide - $0.906 | 1.00 gram zinc - $0.212 | 1000 grams of Zinc Iodide = $1,923.00 | 1000 grams of Zinc Ioidide = $212.30 | Focus Question Should chemists prepare Zinc Iodide, from its Elements or from a Double Replacement Reaction between Barium Iodide and Zinc Sulfate?
0.00079 moles EDTA4- c. 0.00079 moles ZnI2 d. 0.0517 grams of ZnI2 are in the sample e. 0.0517/0.237= 21.8% f. Error Is 6.34% Lab Report: Part 1: In this lab we used the following supplies: * Zinc Iodide * Na2H2EDTA(s) * Calmagite indicator solution * pH 10 buffer solution * 6M Acetic Acid * Unknown Zinc Compound The main purpose for this part of the lab was to determine the amount of zinc ion in a sample of ZnI2 by titration. The two types of zinc: * Zinc iodide made by zinc and iodine * Commercially purchased zinc iodide (the
Results APPEARANCES OF MATERIALS USED Substance Physical Appearance Zinc Carbonate White; powderish Calcium Hydroxide White; powderish; like zinc carbonate 3 M HCL Clear liquid, resembles water 20 mesh granular zinc Grey, metallic, shiny 3% hydrogen peroxide Clear liquid; resembles water Manganese dioxide Very dark grey, black and powdery Copper sulfate Blue, crystalline in structure. Sky blue Zinc iodide Very dark purple, shiny and crystalline in structure 0.1 M acetic acid Clear liquid, resembles water Zinc oxide Very white powdery substance RAW RESULTS Data Specifided (Page 112 CRC handbook) Raw data Volume of Gas Collection Bottle (Average of 3 Trials) 14.04mL Mass of boiling tube (empty) 41.57g Mass of boiling tube with zinc carbonate 43.42g Mass of zinc carbonate 1.75g Volume of water in gas collection bottle after reaction 78.5mL Volume of gas product collected 185.2mL Mass of solid product with boiling tube after reaction 1.11g QUALITATIVE TEST RESULTS Group # Test Observation: Standard Positive/Negative Observation: Experimental Positive/Negative 1 H2 HCL + Zinc bubbling + flaming stick POP! + + flaming splint no POP - 2 CO2 Turned cloudy + Negated from experiment Negated from experiment 3 O2 MgO2 + Hydrogen Peroxide bubbling. Glow stick re-ignited + + wooden splint; glowing stick went out - 4 H2) Added 1 pea size CuSulfate + 1 drop of deionized water; blue, positive + Copper sulfate did not change color when put into wet filter paper - 5 Zn (OH)2 Zinc iodide + 3mL H2O Clear suspension + Visual inspection; cloudy. Acid test= solid + 3M Acetic acid cloudy + 6 ZnO ZnO + Heat yellow Zn Cooled White + ZnCO3 + heat yellow solid.
In this step, as we watched the chemical reaction with the solids, we noticed a thinning in the substance. Also, the solids became lighter and moved to the top. When stirred, the solution began to turn green and then back to light blue, where copper began in the end of the first step. A combination reaction took place, and the balanced equation is: CuOs+H2SO4aq→CuSO4aq+H2O(I) Following this step, step 5 began, in which we added 300 mg of zinc to the solution. Once the zinc was added slowly to the solution, a gas was released and the solution began to change colors.
To observe the change in properties of various synthesized copper compounds in order to identify the reactions and products being formed. Secondly, to become familiar with methods of separating compounds through decanting, heating with Bunsen burner and suction filtration system. In doing so, be able to recover copper metal and interpret the resulting percentage yield by applying the law of conservation of matter. Upon combining 20.0mL of NaOH to 10.0mL of Cu(NO3)2 and stirring the solution, there was a darkening of the initial blue color. Adding distilled water to the solution lowers the initial intensity of the blue color, bringing back to a lighter blue.
6.) In step 6 we added 4 grams of zinc to the solution. When we added the zinc it immediately began to fizz followed by the formation or red clay like solid that floated on the surface of the solution. Reaction 1: Copper metal To Copper Nitrate Cu(s) + 4HNO3(aq) Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) Cu + 4H1+ + 4NO31- Cu2+ + 2NO31- + 2NO2 + 2H2O Cu + 4H1+ + 2NO31- Cu2+ + 2NO2 + 2H2O Reaction 2: Copper Nitrate to Copper Hydroxide Cu(NO3)2(aq) + 2NaOH(aq) 2NaNO3(aq) + Cu(OH)2(s) Cu2+ + 2(NO3)1- + 2Na1+ + 2OH1- 2Na1+ + 2NO31- + Cu(OH)2 Cu2+ + 2OH1- Cu(OH)2 Reaction 3: Copper hydroxide to copper oxide Cu(OH)2(s) + heat CuO(s) + H2O(g) Reaction 4: Copper oxide to copper sulfate CuO(s) + H2SO4(aq) CuSO4(aq) H2O(l) CuO + 2H1+ + SO42- Cu2+ +SO42- + H2O CuO + 2H1+ Cu2+ + H2O Reaction 5: Copper sulfate to copper metal