25 ml of diluted unknown acid solution to 100ml beaker by using 25 volumetric pipet. 10ml of deionized water and 3 drops of phenlpthalin indicator the beaker labeled as 3. Potentiometric titration acid solutions 125 ml of NaOH was obtaining in a beaker and 50 ml of NaOH transfer to buret the tip and the meniscus is at below 0 ml. one magnetic stirring bar placed in a beaker contain one of the known solution on a stir. The pH recorded by using pH electrode before adding NaOH.
g Wait another 10 seconds. Then remove a second drop of the mixture to add to the next drop of iodine. h Repeat step g until the iodine solution and the amylase/ buffer/ starch mixture remain orange. i You could prepare a control drop for comparison with the test drops. What should this contain?
10 drops of each solution was added to the appropriate centrifuge tube. 6 M NaOH was added drop wise to each solution until a precipitate was formed, or until 20 drops were added. Another 10 drops of 6 M NaOH were added to the solutions that formed a precipitate. Again, 5 centrifuge tubes were labeled for the same 5 cations and 10 drops of each solution were added to the appropriate centrifuge tube. The 15 M NH4OH was added drop wise until a color change occurred, or until 20 drops were added.
Clean up lab Data: Trial | # of Dye Drops | Color | 1 | 2 red, 1 yellow | Very dark red | 2 | 1 red, 1 yellow | Light colored red | Analysis: By first placing two drops of red dye, and one drop of yellow dye into the 10ml of water, the color became too dark of a red to match the controlled substance. When observing the two dyes mixed together, the red color was completely dominant over the yellow color. After this observation, taking away one of the red drops of water, and only placing one drop of red dye, and one drop of yellow dye into 10ml of water, almost perfectly matched the controlled color of a light red. As the controlled color was reached, there was not a need for a third trial. The hypothesis was not correct.
Materials and Methods To first create the three distinct solutions, 50mL of phosphate buffer with a pH of 6.84 was poured into a 150mL beaker with 20 drops of 0.04% Bromothymol blue indicator. 5mL of the solution was then added to three separate 50mL beakers. 1mL of HCl was added to one of the three beakers and labeled ‘Yellow’, 1mL of NaOH was added to another and labeled ‘Blue’, and 1mL of distilled water was added to the last beaker and called ‘Green’. The spectrometer was prepared and left to warm up before calibrating it. Taking the three solutions prepared earlier, each was transferred to three separate cuvette while filling the fourth cuvette was filled with distilled water.
Then, 10 mL of distilled water was added to the precipitate. And 9 mL of H2SO4 was added drop by drop. For the last step, 0.3056g of zinc was weighed out, and was added in reaction mixture to react. After decanted, 5 mL of 6 M HCl was added to react with remaining zinc. A vacuum filtration apparatus was assembled.
The purpose of massing before and after crushing the tablet was to determine if any of the tablet was lost during the crushing process. After that, 8 mL of 1M hydrochloric acid was added to a 50 mL beaker with the powder from the crushed tums tablet. When the hydrochloric acid was added, a reaction occurred in which the CaCO3 from the tums tablet neutralized the HCL. The solution could be observed fizzing and bubbling heavily for roughly 15-20 seconds, and subsided completely in about one minute. After that, a pH sensitive color indicator, phenolphthalein, was added, and the solution was titrated with 1M sodium hydroxide.
After 5-10 minutes with the heat we started to observe a color change, after the CuSO4 (copper sulfate) cooled it had turned a grayish/ blue color. Using the electronic balance we weighed the CuSO4 with the crucible, which weighed 19.972 and subtracted the original weight of the crucible (19.972-19.071), which came to about .901, the weight of the leftover CuSO4. Heating to a constant mass is the only way to insure that the reaction is complete. It means checking the mass to ensure it is near each other at the end of a reaction. The color change in the copper sulfate when we heated it indicated that all of the water has evaporated, to be sure, we heated and weighed the crucible and CuSO4 again, and it came out to be .901g again.
Rates of Reaction Lab - Concentration Name: _________________________________________ Date: ___________ Purpose: To determine how concentration affects the rate of a chemical reaction Materials: 100 ml graduated cylinder, 10 ml graduated cylinder, 100 ml beaker, 0.2M Na2S2O3, 3M HCl, water, stopwatch Procedure: 1. You will be completing 5 trials using the amounts in the table below. For each trial: Trial 1 2 3 4 5 Na2S2O3 10 ml 20 ml 30 ml 40 ml 50 ml Water 40 ml 30 ml 20 ml 10 ml 0 ml a. Use your 100 ml graduated cylinder to measure and add Na2S2O3 (aq), and H2O to the 100 ml beaker. b.
Title: The effect of concentrations of water and sucrose solutions in dialysis tubes on the diffusion of water of each tube as measured by scales weighing each tube and comparing it to its starting weight under the conditions of ten minute intervals, five milliliters of each solute and beakers filled with the same amount of solution. Abstract: This osmosis lab was done to show how water moves from high to low concentrations across a selectively permeable membrane. Four dialysis tubes were used in the experiment, one tube filled with 5 mL of tap water, the second filled with 5mL of 20% sucrose solution, the third filled with 5mL of 60% sucrose solution, and the fourth filled with 5mL of tap water. All the tubes were weighed initially, and then submerged into beakers. The first three were submerged in tap water-filled beakers, and the fourth tube was submerged in a beaker filled with 60% sucrose solution.