What should this contain? j Count up how many iodine drops you have used, each one equals 10 seconds of reaction time. k Repeat the whole procedure with another of the pH buffers or pool your results with others in your class. l Collect repeat data if there is time. m Plot a graph of time taken for starch to break down against pH.
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.
The pH recorded by using pH electrode before adding NaOH. The solution titrated by 2 ml of NaOH each time and the pH recorded until the color change. These steps were done for the two known solutions and the unknown solution. Part 2 10 ml of vinegar placed in 100ml volumetric flask and deionized water added until the mark. The solution transferred in 150 ml beaker labeled as beaker #1.
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.
After the mixture was heated, there was solid on the bottom and liquid on the top of the flask. The set up was let cool to room temperature. Next, we decanted the mixture in to a clean 100 ml beaker. We rinsed the remaining solid with 10 ml of DCM and swirled the mixture. The mixture was decanted again in to the same beaker.
Boil at least 10 minutes. 7. While the metal is still in the boiling water bath, measure the temperature of the boiling water carefully with a thermometer and record to tenths, one decimal place, in Data Table 2 8. After the metal has been heating 10 minutes, remove the metal from the boiling water bath using the string. Immediately transfer the metal into the calorimeter cup so that the water covers the metal.
Controlled The controlled variables of the experiment were: A. The volume and concentration of the Hydrochloric acid. B. The concentration of the Sodium Hydroxide. Equipment List * Boiling Tube * 10 cm3 1mol dm-3 Hydrochloric Acid (HCL) * 15 cm3 1mol dm-3 Sodium Hydroxide (NaOH) * pH and Temperature Probes * Data Logger * Measuring Cylinder ‘ * Boiling Tube * Teat Pipette Method * Add 10ml of Hydrochloric acid, measured in a measuring cylinder, into a boiling tube.
.40g of NaH_2PO_4, and .40g of Na_2HPO_4 was measured into a 150 mL beaker. 50mL of distilled water was then measured in to a graduated cylinder and added to the 150ml solution of NaH_2PO_4 and Na_2HPO_4. 20 drops of the .04% Bromothymol blue solution was then also added to the buffer solution. After adding the 20 drops the tint of the liquid changed to a light green. The Vernier pH probe was calibrated and used to determine the pH of the phosphate buffer solution which was 6.81.
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.