First of all, the purpose of this lab was to determine the water’s vapor pressure at different temperatures as well as to measure the molar heat of vaporization of water using the Clausias Clapeyron equation. The first concept out of many represented in this lab is the ideal gas law. The ideal gas law is used to get the number of moles of air trapped in the 10 mL graduated cylinder. Once we cooled the system so that water vapor is extremely minute, and then we determined the number of moles of air using the ideal gas law. The number of moles of air equals to the pressure (in atm) times volume divided by constant times temperature. One would assume that when the water is heated to 80 degrees, the number of air molecules in the air bubble would decrease, but it actually stays constant. This is due to the fact that there is no air coming in or out of the cylinder. As the temperature gets closer to 80 degrees, the number of air molecules stays the same but the water vapor increases. And the bubble expands to keep the pressure at the same level. The ideal gas law was also used when the partial pressure of air in the gas mixture is calculated. This is gotten from number of moles multiplied by the constant and the constant and the whole thing divided by the volume.
Use glassware as directed by your instructor. Place a test tube placed inside a beaker with ice water to collect the product from the apparatus. Obtain the 10mL round bottom flask from the apparatus. Obtain two graduated cylinders of 10mL. On one graduated cylinder measure 4mL (85% H3PO4) of Phosphoric Acid and pour into the 10mL round bottom flask. On the other graduated cylinder measure 3mL of Cyclohexanol and pour into the flask as well. With a pipet add 5 drops of Sulfuric Acid (H2SO4) into the flask. Attach the round bottom flask to the distillation apparatus. Place thermometer with rubber stopper on the apparatus to obtain the temperature Start with the water flow through the condenser. Turn on and heat the reaction until the product starts to distill. Distill and collect until thermometer temperature rises to 85˚C. Once there is no more product to collect obtain the test tube of product. Two layers should be formed, top layer of cyclohexane and bottom layer with water. Obtain a pipette and remove the bottom layer (water) if any. Add 10% (5mL) of Sodium Bicarbonate (NaHCO3) to nuclearize any acid in the solution. Mix well and remove once again the bottom layer of water with pipette. Add 5mL of water and mix well to wash the top layer. After the two layers form again, remove entirely the bottom layer of water and add a few pellets of Calcium Chloride. Obtain a 50mL or 100mL beaker and weigh.
Second, a small sample of solutions must be collected and transferred to the beakers by pouring or pipetting from the 500 mL Erlenmeyer flasks containing the solution. Third, a clean wooden stick must be dipped into the solution, soaked for three to five seconds, and put to the flame created by the bunsen burner. It is very important to make sure that that the wooden stick should not catch fire and this may have to be done this several times in order to get a good color. Next, the color of the flame must be recorded in detail and the wooden stick must be ran under some running water to cool it off. Finally, the stick must be discarded into the trash and a new wooden stick must be obtained. Dipping the wooden stick into the solution and put toward the flame must be repeated for the remaining solutions and when you are all done all of the solutions , these solutions should be poured down the drain with a lot of water and rinsed with soap and water. Finally, the labels should be cleaned off, and the beakers should be left upside down to
5.) One at a time, place your test tubes in the water bath and heat the first test tube to 25 , the second to 50 , the third to 75, and the last to 100 degrees c. Remeber to stir with your stirring rod every so often.
It was then placed in the ice bath, in which immediately the can slightly collapse on itself. In part two of the experiment, the prepared ice bath temperature measured at 1°C (T2). While the heated bath temperature stabilized around 85°C (T1) after 5 minutes, where it also began to simmer. The test tube with the rubber stop in the heated bath had no water for the entire 5 minutes. When the test tube was placed inside the ice bath for 5 minutes water appeared to flow inside the test tube. The amount of water that flowed into the test tube measured at 5 mL (Vw). When determining the volume of the test tube in the 100 mL graduated cylinder with 30 mL of water, it displaced the water up to 74 mL. Thus determining the volume of the test tube as 34 mL
After the water, has been boiling for 10 minutes, and the temperature inside the test tube has been stable for 5 minutes, record the temperature and remove the thermometer.
With the LabQuest device in hand, we then attached the Gas Pressure Sensor to channel 1, and the Temperature Probe to channel 2. The group then retrieved the rubber stopper assembly and attached the end of the tubing to the open stem of the Gas Pressure Sensor while leaving the valve stem in the open position. To hold the flask down in the water bath, we placed the glass stir rod into the opening of the rubber-stopper assembly and then insert the assemble into the neck of the 125 mL Erlenmeyer flask with a twist to make sure of a snug fit. We then closed the 2-way valve. Using the thermometer holder, we attached the glass stir rod at the base next to the rubber stopper, and placed the flask into the ice bath. Our group then fastened the thermometer to the ring stand. After procuring the 3-prong clamp we used it to hold the temperature probe away from all sides of the glass while keeping the probe submerged several inches deep. The group then placed the flask and assembly onto a hot-plate and recorded temperature and pressure data. We then turned the hot plate on and start recording data at 15 degree intervals until boiling occurred.
Our project for the unit 2 test will be a candle and water demonstration. This will show the different relationships between temperature, pressure, and volume.
We must first begin the today’s lab by connecting the thermometer that digitally detects surrounding temperature to the Lab Pro Interface located on the computer via...
4. Pour about 300mL of tap water into the beaker. Set up a hot-water bath using a hot plate, retort stand, and thermometer clamp. Alternatively, use a Bunsen burner, retort stand, ring clamp, thermometer clamp, and wire gauze.
Wait until the water boils and record the temperature to make sure that it is 100 degrees
Now, assemble and arrange all of the needed supplies so that they are easily accessible. Connect the IV tubing to the solution bag and allow the fluid in the bag to run through the entire length of the tubing, also known as priming the tubing. When this is done, clamp the tubing closed. You will then need to tear several pieces of tape, six to eight inche...
In a Styrofoam cup, record the temperature of the 200 ml of cold water. This is 200 g of water, as the density of water is 1 g/ml.
For simple distillation, I added 4 mL of a 10-20% ethanol-water mixture to a 5 mL round-bottomed long-necked flask. I joined the flask to a distilling head fitted with a thermometer through...
The last part of experiment 5, was learning about specific gravity and temperature. Specific gravity does not have any units, it is unitless. When measuring for the temperature, we used a thermometer to calculate the Celsius of the water, 10% sodium chloride, and isopropyl alcohol. The specific gravity uses a hydrometer to measure the gravity of the liquids. Using the hydrometer, to figure out the measurements we have to look at it from top to bottom. The water for specific gravity was .998 while the temperature of it was 24