Controlled The controlled variables of the experiment were: A. The volume and concentration of the Hydrochloric acid. B. The concentration of the Sodium Hydroxide. Equipment List * Boiling Tube * 10 cm3 1mol dm-3 Hydrochloric Acid (HCL) * 15 cm3 1mol dm-3 Sodium Hydroxide (NaOH) * pH and Temperature Probes * Data Logger * Measuring Cylinder ‘ * Boiling Tube * Teat Pipette Method * Add 10ml of Hydrochloric acid, measured in a measuring cylinder, into a boiling tube.
Mix the elements with cyclohexane, observe the color of solution, and record it. 5. Record the relative solubility of the elements in either cyclohexane or water. Experiment 2- Displacement reactions of halogens 1. Mix either chlorine solution, bromine solution or iodine solution with either potassium chloride solution, potassium bromide solution or potassium iodide solution.
When the blue colour of the starch-iodine complex appears, stop the clock and write down the time in the Results Table. 5. Repeat the experiment using the concentrations outlined below: Test | Concentration of Reagents/ mol dm-3 | | [Na2S2O8] | [KI] | 1 | 0.10 |
Ocean County College Department of Chemistry [Observations of Chemical Changes] Submitted by Andrew Grimm Date Submitted: 5/31/14 Date Performed: 5/31/14 Lab Section: Chem-181DL2 Course Instructor: Amal Bassa Purpose The main goal in this experiment is to observe the properties of simple chemical reactions, and relating their chemical properties to household products. Procedure To begin this experiment I placed two drops of NaHCO3 into well A1 of the 96-well plate, and then added two drops of HCl into well A1. Next I placed two drops of HCl into well B2, and added two drops of BTB, and observed the color. Then I placed two drops of NH3 into well C1 and added one drop of BTB, and observed the color. Next I added two drops of HCl into well D1, and then added two drops of blue dye, and recorded what I saw.
Observations: * Solution turns green and bubbles * Warm to the touch * Brown gas produced * Copper Dissolves Reaction 2: Copper (II) Nitrate with Sodium Hydroxide Cu(NO3)2(aq) + 2NaOH(aq) Cu(OH)2(s) + 2NaNO3(aq) Net ionic: Cu2+(aq) + 2OH-(aq) Cu(OH)2(s) Type of Reaction: Precipitate Reaction Observations: * With addition of water, the solution becomes blue, thick, and slime-like * When added to litmus paper, paper turns dark blue * Dark blue shows that the solution is basic Reaction 3: Heating Copper Cu(OH)2(s) CuO(s) + H2O(l) Net ionic: Cu(OH)2(s) CuO(s) + H2O(g) Type of Reaction: Redox Reaction: Cu is oxidized from 2- to 2+. The reducing agent is Cu(OH)3 Observations: * While heating and stirring, solution turns greyish blue, then becomes black * Cool water mixes, solution settles to the bottom * *NOT ALL WATER WAS POURED OFF Reaction 4: Copper (II) Oxide with Sulfuric Acid CuO(s) + H2SO4(aq) CuSO4(aq) +
In the first tower, ammonia (NH3) bubbles up through the brine, where it is absorbed. Then, in the second tower (known as the solvay tower), carbon dioxide (CO2) gas passes through the ammoniated brine, and sodium bicarbonate (NaHCO3) precipitates out of the solution. In a similar fashion, the Athenium Baking Soda Company (“ABSC”) produces baking soda by reacting crystalline ammonium hydrogen carbonate with brine, as follows (Eq. 1): NH4HCO3(s) + NaCl(aq) → NaHCO3(aq) + NH4Cl(aq) (Eq. 1) In addition to sodium chloride, brine often contains potassium chloride, lithium chloride, and calcium chloride (i.e., KCl, LiCl, and CaCl2, respectively).
3. Calculate the mass of baking soda,NaHCO3 , and find the percentage of baking soda in the unknown mixture. ※ Data and observations (a) Table 1: Percent yield of Na2CO3 from baking soda Percent yield of Na2CO3 from baking soda Trial 1 Trial 2 Mass of flask + NaHCO3 95.12 g 93.45g Mass of flask 94.15g 92.03g Mass of NaHCO3 0.97g 1.42g Mass of flask + Na2CO3 95.01g 93.12g Mass of Na2CO3 (actual yield) 0.86g 1.09g Mass of Na2CO3 (theoretial yield) 0.61g 0.90g % yield of Na2CO3 140% 120% (b) Table 2: Percent of baking soda in Unknown Percentage of NaHCO3 in an unknown mixture # C Trial 1 Trial 2 Mass of flask + unknown mixture #C (before heating) 95.81g 94.85g Mass of flask 94.15g 92.03g Mass of unknown mixture (before heating) 1.66g 2.82 g Mass of flask + residue (after heating) 95.20g 93.80g Mas of H2CO3 (H2O + CO2) (after heating) 0.61g 1.05g Mass of NaHCO3 in the unknown mixture 1.65g 2.84g % of NaHCO3 in the unknown mixture 99.0% 101% ※ Calculations For table 1: Theoretical yield of Na2CO3 for trial 1