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.
Chemistry: Molarity and Stoichiometry Directions: Using the definition of molarity, the given balanced equations, and stoichiometry, solve the following problems. Please submit your work via the link provided. 1. Calcium hydroxide (“slaked lime”) and sulfuric acid react to produce calcium sulfate and water according to the following balanced equation: Ca(OH)2(aq) + H2SO4(aq) ⋄ CaSO4(s) + 2 H2O(l) a. How many liters of 0.2 M calcium hydroxide do you need in order to have 6.0 moles of calcium hydroxide?
The color starts out as a reddish brown color, and then, when swirled, becomes a gold yellowish color, and slowly becomes transparent clear at the end of the reaction. As Zinc and Iodine is reacting, the bottom of the test tube would become hot, but slowly, about 5-10 minutes, will begin to cool down to room temperature. On the atomic levels, the atoms of both Zinc and Iodine are reacting causing that exothermic reaction to occur. The atoms would combine together to form ZnI2, and cause a color change because of the interaction between the particles. When the water is evaporated, a white compound of zinc iodide is formed.
Lesson written by Carolina Sylvestri Experiment: Reaction Between Ions in Aqueous Solutions The Monster Mash Background: Ionic solids dissolve in water to form aqueous solutions which conduct electricity. These solutions contain both positive and negative ions in such numbers that their net electric charge is zero. In this experiment, you will mix various ionic solutions, two at a time, to determine which combinations form precipitates. Knowing which ions are present makes it possible to deduce which of the possible ion combinations are responsible for the precipitates. From your data table, it will then be possible to generate a solubility table.
Contents Abstract – Page 2 Summary of Results – Page 3 Focus Question – Page 5,6 What if… - Page 6 Confidence Report – Page 7,8 Abstract Summary of Results Observations of Reactions – Trials 1 , 2 & 3 | Dissolving Barium Iodide and Zinc Sulfate in deionized water | As the substances dissolve the water becomes cloudy and acquired a white tint. | Centrifuging up the solution obtained in previous reaction | The precipitate and the liquid seperated, and there was more precipitate in one of the test tubes. The precipitate was a thick white color, not transparent. | Heating the Precipitate in a boiling tube containing 2 boiling chips | The mixture began producing a large amount of bubbles, as we continued heating it only white powder remained. | Observations of Chemicals | Zinc Sulfate | Powder of a white solid | Barium Iodide | Powder of a white solid.
When the hydrate is heated, it easily loses water molecules attached and becomes an anhydrous salt. The corresponding chemical reaction for hydrated magnesium sulfate can be written as |MgSO4•7H2O ( MgSO4 + 7H2O |(1) | where MgSO4 is the anhydrous salt. Usually,
Theoretically speaking, if we use one granule of zinc and one granule of iodine opposed to one granule of Barium Iodide and one granule of Zinc Sulfate, the cost would be $.2123 in total for the elemental reaction and $.9265 for the double replacement reaction. In terms of safety, it is safe to say that the safer thing would be centrifuging since we are
I believe we did our procedures accurately. The precipitate was Zinc hydroxide which is amphoteric in nature. Meaning it can react both with acid and base to form salt. We got a white precipitate of zinc hydroxide and it reacted to make salt with both the base sodium hydroxide and the acetic acid. Our result would have been clearer to observe if we centrifuged it long enough because we might have lost some of the precipitate while washing it since it was not centrifuged long enough.
Magnesium sulfate was used to absorb water and simple filtration was used to remove magnesium sulfate. Rotary evaporator with a steam bath was designed to remove the solvent. Finally gas chromatography was used to identify the purity of the limonene. 2. Mechanism 3.