We came to this conclusion by calculating the density of post 1983 pennies using the equation; massvolume=density. WE conducted three trials of this experiment and found the average density of a penny to be 6.92 g/cm3. The accepted value of a post 1983 penny is 7.05g/cm3. Our percent error was 1.8%. In order to have valid results, your percent error must be equal to or below 3% and ours was below.
This test tube was placed in the spectrophotometer, every thirty seconds a reading was taken, this continued on for three minutes. After three minutes the tube was removed and cleaned. This process was repeated for runs 2, 3, and 4. for run 5a. through 5d. each tube was placed in a different temperature changing environment (freezing, cooling, heating and boiling).
Of course the saturated solutions take time this experiment is done in a two day lab setting part one should be completed during the first day and ready for use on day two. Remember because Le Châtelier’s principle if you don’t filter the solution will rise. The removal of OH- from the UN filtered solution will cause more Ca(OH)2 to be dissolved for the equilibrium to restore. The second part of this lab takes knowledge from past experiments done in this laboratory. Using the Primary method used to standardize the concentration of HCl, this will bring much lower percent error in the Ksp For this standardization sodium carbonate should be used for determining the amount of hydroxide in the solution.
In this titration, three major steps involved were first measure out an amount of known solution, add indicator and three, to titrate using unknown solution. At the first colour change the titration would stop. Abstract The purpose to this lab is to standardize an approximately 1 mol•L-1 solution of hydrochloric acid. There were many steps taken in this titration but the main steps were measuring out the amount of known solution, adding the indicator and finally, titrating the solution until the first colour change. In each trial, the initial reading, final reading and the volume of HCl used was recorded down as quantitative results.
Repeat steps 1-6 until three trials have been recorded. Results: Trial | Initial Volume | Final Volume | Total Volume | Color of the Solution | pH | 1 | .60mL | 8.6mL | 8mL | Bright Pink | N/A | 2 | 8.6mL | 14.9mL | 6.3mL | Semi-BrightPink | N/A | 3 | 14.9mL | 21.3mL | 6.3mL | Pale Pink | 7 Yellow | Analysis: The data that we collected, made us infer that the indicator, phenolphthalein, changes to a bright pink color in the presence of a basic solution. Our data also showed that the neutral solution had a lesser amount of NaOH than HCl. This would mean that the NaOH was more concentrated than the HCl. We then calculated the molarity of NaOH with the volume found in our data.
Every few minutes, the lid of the crucible was lifted carefully with a tong to see if the magnesium had started to burn and also to left some air enter the crucible to make the experiment more efficient. 6. When the magnesium had completely reacted, the crucible was heated strongly without the lid on for few minutes. Then, the crucible was placed on gauze for it to cool down. 7.
To get accurate result, this titration process are repeated for another two times. The entire procedure by which we obtain the molarity of a solution of one substance (NaOH) from an accurately known amount of another substance (KHP) is called standardization. The average molarity of the sodium hydroxide solution will be used in the next experiment. The second experiment is conducted to determine the molarity of acetic acid and mass percent in vinegar. 100mL of distilled water was added to 10mL of vinegar and followed by 1mL of NaOH was pour into the solution.
Once the buffer tablet has dissolved into the water, add 10 ml of starch solution. 3. After the starch solution has been added, add 10 ml of enzyme solution to the current solution, simultaneously start the timer and record at 1 minute intervals. 4. In addition, place iodine in the dropping tile in order to identify if starch is currently present.
Before the experiment, take out the fridge water and measure out three cups and pour it into the one quart pot and measure the water temperature before placing it on the stove. Then turn the stove on to maximum heat as well as the timer. While the water is reaching to the boiling point measure and note the temperature for every minute. Next, let the stove and the pot cool down for few hours. Then take jug with room temperature water and pour out three cups into the pot.
Note: The experiment was done at room temperature and not 0 degrees so of course , the result will be different than the one known, which is 300000 j/kg , but as the main point of this experiment is to see if latent heat changes with the change of time , so it won’t affect the experiment . Results : Set A: Time = 3 minutes = 180 seconds Voltage(v) | Current(A) | Weight of empty beaker (kg) | Weight of beaker after melting of ice (kg) | Weight difference | Heat Energy (J) | Latent Heat (J/kg) | 12V | 2.17A | 0.398 kg | 0.404 kg | 0.006 kg | 4687.2 J | 781200 j/kg | Set B: Time = 2minutes = 120 seconds Voltage(v) | Current(A) |