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
17. Press START and turn on the stir bar. 18. After 10 seconds have elapsed, add hot water sample 19. Press STOP when the thermograph stabilizes 20.
Steps 1-10 were repeated using Copper (II) Sulfate and sodium hydroxide solution Part B: 12. 5 ml of hydrochloric acid was poured into the larger test tube. 13. One scoop of sodium bicarbonate was put into the beaker 14. The test tube was placed in the beaker and the total mass of the reactants, test tube and beaker were determined using the balance.
Using a test tube holder, heat the R tube over the Bunsen burner, moving the tube in a circular motion until all the water has evaporated. The P tube will be carefully heated next, for about 10 minutes, until all the water has evaporated, and there is a white substance in the tube. After the water has evaporated, continue heating the tube over the burner for a minute longer, being careful to watch out for purple gas and yellow spots. The P tube
Begin by adding 1 mL of rubbing alcohol to test tube and attach a thermometer to it. b. Place assembly in water bath and begin to heat beaker c. As isopropyl alcohol begins to boil, bubbles begin flowing from the capillary tube d. While temperature is decreasing, record the temp. when the last air bubble comes out of the capillary tube. e. Let assembly cool down and repeat process two more times.
To the second, add 10% NaOH dropwise until the pH is 14. (To do this, add a couple of drops of NaOH to the tube; stir thoroughly with a stirring rod; then touch the stirring rod to a piece of pH paper to check your pH.) To the third, add 0.5% sodium bicarbonate solution to pH 9, and to the fourth, add 2% HCl to pH 2. Record your observations on the data sheet. Repeat the above tests using 2% casein solution.
Lab 4: Determination of Percent by Mass of the Composition in a Mixture by Gravimetric Analysis Introduction Thermal gravimetric analysis is used to determine the percent by mass is used to determine the percent by mass of a component in a mixture. When a mixture is heated to an appropriately high temperature, one component in the mixture decomposes to form a gaseous compound. The mass of this particular component is related to the mass of the gaseous compound. In this experiment, the percent by mass of sodium hydrogen carbonate (NaHCO3) and potassium chloride (KCl) in a mixture will be determined. 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.