Questions On Uncertainty Information On The Measuring Variables

For the test tube with the ratio of Acetylene to air is 1:3, a flame traveled down a test tube even slower, there was a slight popping noise and black residue . For the test tube with the ratio of Acetylene to air is 1:7, a flame traveled quickly down a test tube, popping noise and less black residue. Refer to table 1 for the specific lab results.

10) The tape was used to measure gas accumulation in the balloon after 1minute. Measurement and qualitative observations were recorded.

An automatic pipet was used to measure 0.450 mL water and 0.165 mL acetic anhydride and was added to the conical vial. A spin vane was placed into the vial and an air condenser was attached.

Please Note: This lab involves a lot of waiting for the gas collection. Make sure you allot yourself the full three hours to perform the experiments.

1. Carefully measure the volume of the trapped gas using the graduations (markings) on the side of the container.

The next step in this lab is to rinse the Erlenmeyer flask with distilled water down the drain and then repeat the experiment, this time adding 10 ml of 0.10M KI and 10 ml of distilled water to the flask instead. The flask should again be swirling to allow the solution to succumb to the same temperature as the water bath and once it has reached the same temperature, 10 ml of 3% H2O2 must then be added and a stopper must be immediately placed on the flask and recording should then begin for experiment two. After recording the times, the Erlenmeyer flask must then be rinsed again with distilled water down the drain. After rinsing the flask, the last part of the lab can now be performed. Experiment three is performed the same way, but instead, 20 ml of 0.10 ml M KI and 5 ml of distilled water will be added and after the swirling of the flask, 5 ml of 3% H2O2 will be added. After the times have been recorded, data collection should now be complete.

The volume of a small test tube and a thin-stemmed pipet were determined in this section of the lab. Water was poured into a small test tube until the water reached the very top edge of the test tube. The test tube was then emptied into a plastic 25 mL graduated cylinder and volume was measured and recorded into data table 3. A think-stemmed pipet was completely filled with water. Drops were carefully counted and emptied into the empty plastic 25 mL graduated cylinder until the water level reached 1 mL. The number of drops in 1 mL was recorded into data table 3. The thin-stemmed pipet had a total volume of 4 mL and that was also recorded into data table 3.

4. Remelt the contents of the tube and add the counterpart component based on the given schedule. Ask the demonstrator to adjust the cooling water between mixtures. During the experiment, record and plot the data obtained for all mixtures listed. The experiments are stopped as follows:

Of all the variables that affect climate throughout the episode, the variable that was the most prevalent in the group was certainty. This is the case, because for the duration of the whole trial, there were moments of certainty from Fox Mulder. For example, Mr. Mulder conveyed a sense of certainty towards Dana Scully by saying, “I know what I’m doing.” Another example is when a female witness was testifying for Fox Mulder and Mr. Mulder said to Skinner, “No, it’s ok, let her go. Soon after that, Walter Skinner responded disclosing the following, “What are you doing Mulder? She is the last best witness that we have!” Mr. Mulder then countered him by saying, “Doesn’t matter.” Yet another example of a certainty variable that affected climate

8. In order confidently determine what substance my “G9R” was I would have to do over the boiling point experiment a couple of more times. I would turn the gas off and take the Bunsen burner away from the apparatus when the stream of bubbles started coming out from the mouth of the capillary tube. This would allow me to correctly determine when the atmospheric pressure was equal to the vapour pressure.

In addition, it is important to note that the oxygen in the air and the pressure of the cylinder are directly related, as oxygen is removed, the pressure of the cylinder is reduced. This lab did not pose many safety hazards, except for Acetic Acid being an irritant. In this lab, we followed the lab procedures found in the University of Chicago’s General Chemistry Lab Manual for the experiment titled “The Oxygen Content of Air”. However, we deviated slightly by increasing the temperature to 54 °C after witnessing little oxidation occurring while using lower temperatures.

The primary aim of this experiment was to calculate the latent heat of vaporisation of nitrogen. Another important aim was to understand the relationship between gas flow, latent heat and the power input.

An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water

However, numeric uncertainty may not be the best form of communication for all users. Most of the work described above was done using university undergraduate students as subjects. It is reasonable to assume the decisions made by this population would be similar to the general population, but there could be subgroups that would make better use of a categorical recommendation. Indeed, using the example of Hurricane Floyd, a majority of residents (64%) followed the evacuation warning, suggesting it was useful to some. It is also possible that some people may do worse when they are given numeric uncertainty information. Some people may not be able to understand or process the uncertainty information, due to limitations in mathematical ability, analytic reasoning, or intelligence, and would instead benefit from a recommendation. The literature supports this idea in specific situations: when faced with a low probability event where the optimal decision is to take precaution, individuals with uncertainty information are more likely to make a risk seeking error, but individuals with a recommendation made fewer errors (Grounds & Joslyn, 2015; Joslyn & Leclerc, 2012).

The Joule-Thomson apparatus (Leybold Didactic, Huerth, Germany) consisted of a glass cylinder with five outlets and a glass filter subdivision. One side of the division was connected to the helium or carbon dioxide gas pressure cylinder that was supplied in the laboratory, a pressure sensor, and a NiCr-Ni thermocouple, which measures the temperature inside that chamber. The other chamber contained outlets for another thermocouple and for the transferred gas. A temperature controlled water bath was used to set the system to the