3. Upon adding 20 drops of NaOH, a white precipitate was formed signifying acidic impurity. In the second NaOH mixture, about 20 drops were administered and no precipitate formed indicating that the ample is more pure than before. Data: Weight of flask = 75.10 grams Weight of the flask with solids =
The goal of this experiment is to find out what is the identity of the unknown hydrate? To answer this question first, we should know what a hydrate, and how to identify a hydrate using the law of constant proportions. A hydrate is a pure substance because it contains water molecules embedded in its crystal structure that does not vary. By heating the unknown hydrate, we can calculate the mass of the hydrated, and the percentage of water in the hydrate.
The hypothesis made, the density calculated in the experiment will stay the same because the density of the unidentified object will never change, was supported. The results support the hypothesis because in every trial the density always came out to 9g/mL. In trial one the mass was 71.16g, the volume was 8mL, and the density was 8.895g/mL, but when rounded to the proper sig fig came out to 9g/mL. In trial two the mass was 71.12g, the volume was 8mL, and the density was 8.89g/mL, but when rounded to the proper sig fig came out to 9g/mL. In trial three the mass was 71.14g, the volume was 8mL, and the density was 8.8925g/mL, but when rounded to the proper sig fig came out to 9g/mL. When averaged the mass was 71.14g, the volume was 8mL, and the density was 9g/mL. Errors that could have occurred are, not calculating the density correctly, not completely submerging the unidentified object with water in the graduated cylinder to get the volume, not rounding the sig figs correctly when finding the density, not measuring the unidentified object’s mass in grams, not measuring the unidentified object’s volume in milliliters, and not writing the correct units with the proper number or not the correct unit at all.
Utilizing the method that the experimenters have come up with, the procedure isolates the variable being tested, which is the paper towel brand. By not changing other aspects of the procedure, other factors have a lower chance of affecting the accurate results of the answer to the main question. Additionally, the method is a quick and simple experiment, causing no use of excessive time than the provided duration. Within the first minutes of the experiment, the experimenters and the advisor realized that the method did not really provide accurate results due to merely estimating the numbers without the use of a graduated cylinder. Changing that aspect of the procedure by using a graduated cylinder to measure the amounts of water instead helped
In the Density Cubes lab we used six cubes that were all the same size but all with different objects such as rice and croutons. When we did that lab we observed
In the Gummy Bear experiment, two gummy bears of the same color were first massed and measured. Then, 150 milliliters of water was placed in a cup along with a gummy bear. Next,
Scientist tested an experiment that tested absorption of water in a cactus through the mass of the same type of cactus. The cactus tested in their experiment was called the Barrel Cactus. Sponges soaked in water surrounded the cactus over the course of a couple days and the scientist tested the mass of the cactus to observe how much water was absorbed. This experiment is similar to our because both tested the mass of the same type of cactus and tested the abortion or extraction of water from the cactus by weighing the mass of the cactus. Even though the scientist tested the absorption of water and we tested the extraction of water through salt, the experiments are similar in many ways.
Once the water was poured into cup D, there was a small amount of bubbling that occurred. The chalk pieces dissolved slightly in the water because the water appeared to have a slight blue color to it. Cup E only contained chalk and served as my control or reference for the original appearance of the
The objective of the sludge lab was to determine how many different pure substances were in the sludge by using the methods and techniques we have learned throughout the year. We had to pick separation methods so we could separate our sludge and then test characteristic properties on our separated liquids and solids. This experiment made us use our knowledge on characteristic properties to pick the ones we should test to help us identify our pure substances. Characteristic properties are properties that help identify a solid or liquid. Each solid or liquid has a certain density, boiling point, solubility, flammability, so if you know what each one is then you can use that information to help you identify your solid or liquid.
The Density Exploration lab called for us to use two different methods to calculate the density of copper with various shapes and sizes. The second experiment called for us to devise an experiment to calculate the differences in density between soft drinks. Rather than calculating using two different methods to calculate for the same substance we had two different soft drinks, diet and non-diet Coca-Cola. We then used two volumetric pipets to measure the volumes of the soft drink, then placed the soda in a beaker to calculate the mass using an analytical balance. The questions that I considered before beginning the experiment were, “How does each method of calculating density affect the outcome?’
3mL of the liquid in each of the vials were added into cuvettes and measured in the spectrophotometer. Before each time point the photo spectrometer was zeroed using a cuvette with 3mL of distilled water. If any of the results were considered unusual the machine was zeroed again and the sample was retested. The results from the spectrophotometer test were recorded in a table. The experiment was repeated six times to gain a sample size of six.
The goal for this part is to test the weight percent solids when the viscosity is changing by a second. Water is slowly added and then the viscosity is checked multiple times to guarantee that the viscosity is as close to 22, 21, 20, 19, and 18 seconds. The amount of water that was added to drop the viscosity down a second was also collected. Table 6: Results of Weight Percent Solids when diluted to specific Viscosities. 22 21 20 19 18 Trial Visc.
This experiment demonstrated water density because the cold water moved beneath the hot water, because it is denser. 5. Was your hypothesis supported or refuted? Explain.
Also, although this likely served no contribution in disheveling the results, using a stirrer of the same material to ensure the separate testing of each substance will be as uniform as
Therefore, this experimentation indicated that the sucrose molecules cannot diffuse from the concentration of the dilute solution, while on the other hand the water molecules diffuse from the dilute solution to the concentrated one. Hypothesis: If the (independent variable) sucrose of the dilute solution is
