It was found that the unknown mixture was comprised of 49.8% NaCl, 36.8% SiO2, and 13% CaCO3. Introduction The key to this experiment is to understand solubility and know how to use the solubility of certain components to separate mixtures. Knowing which components are soluble in the solutes that are available proves to be very advantageous. To start the experiment, the unknown ternary mixture will be added to water to produce a solution that includes all of the components of the original mixture (NaCl, SiO2, CaCO3). Since the sodium chloride is soluble in water, gravity filtration will allow for separation of the calcium carbonate and sand (residue) from the NaCl+H2O (filtrate) solution.
The experiment proves the effect of salinity in the presence of polyacrylate as it absorbs water. The final test of the properties of polyacrylate is to add oil in the water that the polyacrylate will absorb. If the polyacrylate is affected by the salinity level, than the added salt will increase the polyacrylate’s ability to absorb water. Materials & Procedure: Check Pre-Lab Data & Results:
Then, sodium hydroxide would have to be titrated against the potassium hydrogen phthalate to standardize sodium hydroxide to 0.1M as well. Titration is the procedure used to determine the concentration of some substance by the controlled addition of a solution into a reaction vessel (flask) from a burette. By using titration, the volume of the solution delivered from the burette may be determined very precisely. This reliable primary standard solution became useful as a titration was made against the orange juice to find the molarity of the citric acid. The indicator Phenolphthalein was the substance used to signal when the titration reached the point at which the reactants are stoichiometrically equal as defined by the balance reaction equation.
I added a few drops of 3% Hydrogen Peroxide and it resulted in bubble formation. The positive gram stain and positive catalase test indicated that the organism belonged to the Staphylococcus Genus, which meant it was now time to pinpoint the species based on differential and selective biochemical tests. To ensure that my genus identification was correct I performed a Bile Esculin Slant with a fish tail streak on my unknown bacteria. This test resulted in neither growth nor a black precipitate; therefore I could conclude that my unknown was not Streptococci or Enterococci but indeed Staphylococcus. Next I observed the isolation streak on my Blood Agar Plate and found pinpoint, round, entire and flat colony morphology as well as an alpha hemolytic reaction pattern, indicating red blood cell ion leakage which is characteristic of S. epidermidis.
CHEMISTRY HL Investigation 1.2 Standardizing a solution of hydrochloric acid using a standard solution of Sodium Carbonate Candidate name: Amjad Al-Jafari 11 IBDP 1/2/2013 Preparing a standard solution of Sodium Carbonate (A) • Data Collection and Processing: 1. Data Collection: -Mass of Sodium Carbone which is the solute in this solution: 1.26 ± 0.01 grams. -Volume of distilled water which is the solvent in this solution : 250 ± 0.3 cm3 = 0.250 dm3 -Molar Mass of Sodium Carbonate: 2 Na + 1 C + 3 O = 105.99 Observations: Before beginning the experiment we observed that: • Sodium Carbonate is solid powder that has a white color, • Distilled Water is colorless. During the experiment we observed that: • As we started to add the solution of Sodium Carbonate to water its particles started to dissolve in the solvent as we are stirring until all particles are dissolved in the solvent (water). After the experiment we observed that: • However a white solid powder of Sodium Carbonate has been added to water no color change occurred, it stayed colorless, still all particles of Sodium Carbonate has dissolved in water.
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.
At 50C our results indicated a solubility of 89 g/100mL of H2O which was close to the known solubility of 80 g/100mL. Introduction: When a salt, such as potassium nitrate or sodium chloride, is placed in water a dissolving reaction will occur. At first, the positive and negative ions of the salt compound are only attracted to each other. In order for the salt to dissolve, these bonds must be broken so that the ions disassociate from each other. In the water molecules, hydrogen is slightly positive and oxygen slightly negative so they are attracted to ions of the opposite charge, known as dipole attraction.
Neutralization Osaji Obi 3/28/2013 Introduction The objective of this experiment is to determine the neutralization curves for weak monoprotic and polyprotic acids, and to learn potentiometric pH measurement. Pka is also needed to be determined by the equation of –log(Ka). To find that we use half neutralization and titration with a strong acid. Procedure The solution is diluted to the mark with distilled water. A burette with the standardized NaOH solution is filled.
Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water NaOH(aq) + HClaq → NaCl(aq) + H2O(l) Variables Independent The independent variable of the experiment was the amount of sodium hydroxide that we added to the acid. To keep the variable controlled we would measure 1 ml of the sodium hydroxide and pouring that to the hydrochloric acid. Dependent The dependent variables of the experiment were the temperature and the pH number of the mixture. To control the pH and temperature use the electronic probe and data logger. Controlled The controlled variables of the experiment were: A.
In the distilled water, the water will diffuse into the egg through osmosis. This diffusion will occur in order to create an isotonic state between the egg and the solution. Materials and Methods This experiment used * 3 eggs * A scale * Vinegar * Distilled H2O