Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds. Then, add the supernatant into the boiling test tube and repeat this step one more time with another 1 mL of deionized water. Acquire a pair of metal test tube holders and heat the boiling test tube to evaporate the water for 15 minutes. Let is cool after and weigh it. Then, calculate a percent yield of zinc iodide and write a balanced chemical equation and determine the limiting
Fill the burette with 0.005mol dm-3 potassium manganate(VII) solution. 6. Pour some of the thyme extract solution into a 250cm3 plastic beaker. 7. Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid to the thyme extract in the conical flask.
The graph shows a variation as the system heats at a constant volume. The slope of the tangent line to the curve is called the heat capacity at a certain temperature at a constant volume. CV denotes the heat capacity at a constant volume. The equation is as follows: CV is the derivative of the internal energy in respect to temperature. The equipartition theorem says that each term in the total energy expression with either a squared momentum or coordinate contributes the same amount, (1/2)RT to the energy as well as the heat capacity.
A voltmeter was used to measure the electrical resistance of different solutions. * Experiment and Observation: The plastic and glassware used in this experiment was thoroughly washed with hot water and rinsed with distilled water. * * Part I: Preparation of Standard Phosphate Solutions 1. 1.0 ppm standard: 1.00 mL of 10.0 ppm phosphate solution was placed in a 25 mL graduated cylinder and diluted to exactly the 10 mL mark with distilled water then poured into a plastic cup labeled 1. Cylinder was rinsed with distilled water.
Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them. (crucible + sample; WA1 and WB1) Third, we heated both samples on a hot plate for 30 minutes. Fourth, we weighed the samples again (crucible + sample; WA2 and WB2) Lastly, we determined NaHCU3 percentage in the mixture using the following method: WA1 – WA2 x 100% 0.309 WA1 – WA2 x 100% 0.309 * * Results * Theorectically: * Discussion When sodium hydrogen carbonate is heated, new products are formed; sodium carbonate, water vapor, and carbon dioxide gas. This reaction may be presented in a different form with a measure of molecules: @Na2CO3 + H2O + CO2 (solid) (solid) (gas) (gas). Once the reaction of sodium hydrogen carbonate takes place, carbon dioxide gas is released, as well as water vapor.
Nest one Styrofoam cup in another 11. Obtain an exact mass of tap water (45-50g) to serve as cold water 12. Put a magnetic stirrer in the bottom of the calorimeter 13. Secure temperature probe to a ring stand 14. Place temperature probe through hole in cardboard lid and position probe about 1cm above bottom of calorimeter 15.
In the second beaker, place two ice cubes and add water to the 100 mL mark on the beaker. Then add the thermometer Celsius. Record the initial temperature of the water in both beakers. Make one data table incorporating both data sets (tap water and ice cube water) using 30 second time intervals and the temperature in degrees. Place both beakers on the hot plate and turn the hot plate to high.
Using another 125-mL flask, 60-mL of 0.3622 M potassium hydroxide in ethanol was deposited. Both flasks were clamped in a temperature-controlled bath regulated at 50.0˚C. The solutions were then set in the temperature bath for ten minutes to equilibrate. An empty 250-mL Erlenmeyer flask was also clamped in the same water bath. In another flask 50-mL of ice water was deposited with three-drop phenolphthalein.
We used 1g of Na2CO3 -Sodium Carbonate. This would allow for the full precipitate to form. 4) Procedure: Refer to CHE 111 lab manual, experiment Stoichiometry of a Precipitation Reaction on page #104 5) Data / results. We used 1g of Na2CO3 -Sodium Carbonate in combination with 1g CaCl2·2 H2O-Calcium Chloride, Dihydrate to form the precipitate reaction. Na2CO3 aq + CaCl2*2H2O aq = CaCO3 s + 2 NaCl aq + 2 H2O aq Molar Mass: Ca = 40.08 Cl2 = (35.45) x 2 = 70.9 2H2O = (18.02) x 2 = 36.04 40.08 + 70.90 + 36.04 = 147.02 g/mol CaCl2*2H2O Theoretical yield: 1g CaCl•2H2O x 1 mol CaCl•2H2O x 1 mol CaCO3 x 100.09g CaCO3 = 0.68 g CaCO3 147.02g CaCl•2H2O 1 mol CaCl•2H2O 1 mol CaCO3 Mass of weighing dish = 0.6g Mass of filter paper =
Put on a safety goggles. Use a thermometer to measure the initial temperature of the water in the soft drink can. Measure the initial mass on a mass scale. Place the fuel under the soft drink can (If the fuel is half a cashew nut or cheetos stick it to a wine cork using a pin, then wrap the wine cork with a sheet of aluminum foil). Set the stopwatch to 1 minute.