Please help me with procedure with your own words. Gas Law - Determining the Val
ID: 994743 • Letter: P
Question
Please help me with procedure with your own words. Gas Law - Determining the Value of R Purpose: Understand the Ideal Gas law Using dry ice, confirm the value of the gas constant. Background Information Empirical gas laws (Boyle's Law, Charles's Law and Avogadro's Law) can be combined to produce the Ideal Gas Law: PV = nRT or PV/nT = R (a constant) To determine the value of Gas Constant. R, you need to obtain P, V, T and the number of moles of gas in the container. Pressure and Temperature are easily determined by the reading of barometer and thermometer in the lab. Now, you need to find the number of moles (or mass) of the gas and the volume of the flask. In this experiment, you will measure the mass of a sealed flask filled with CO_2 to determine the mass of CO_2 in the flask as well as the volume of the flask. Keep in mind that you already have air in the flask before CO_2 was introduced. Simple weighing of the sealed flask on a balance will give you the mass of the sealed flask with air (density of dry air is 1.2754 g/L in 0.00 degree C, 1.00 atm). Since d = m/V and V alpha T/P, the density of a gas is proportional to P/T or dT/P is a constant. d_1 T_1/P_1 = d_2 T_2/P_2 Based on the average mass of the air (80 % N_2 and 20% O_2), you can also calculate the density of the air under room temperature and pressure, then the mass of the air in the flask. To determine V, you will fill the flask with water, and measure the volume of the water that the flask now contains by pouring it into a graduated cylinder. Now you can determine the mass of the sealed flask with nothing, not even air, in it. Since the volume of the flask does not change, you may want to determine the mass of the flask filled with CO_2, before you add wafer into the flask. A piece of dry ice (solid CO_2) is allowed to sublime in the flask covered with a piece of Parafilm. When the flask has been filled with carbon dioxide and reached room temperature (and the entire solid has disappeared), the air in the flask has been replaced by the carbon dioxide. Therefore, you will have to subtract the mass of air to obtain the covered flask with nothing (not even air) in it. Then, the difference between the mass of the covered flask filled with carbon dioxide and the mass of the covered flask with nothing is the mass of CO_2 in the flask. Now, you should be able to calculate the value of R and compare the value you determined with the accepted value of R. 0 0821 L atm/(mol K). Procedure Obtain a piece of Parafilm. Cover a DRY 250mL Erlenmeyer flask with Parafilm and obtain the mass of the covered flask 3 times. Place a sample of dry ice about the size of a large pea in the flask. Cover it tightly with Parafilm and poke several holes to let extra CO_2 gas escape. CAUTION: You can get frostbite if you hold dry ice. Do not handle it with bare hands. Allow the dry ice to sublime till the solid just disappears. Wait a minute or so to allow the contents of the flask to reach room temperature. If the film is pushed up by the CO_2 gas, make more holes. Reweigh the flask (plus carbon dioxide). Repeat steps 2-4 two additional times for a total of three trials. Fill the flask with water till water surface is flushed with the top of the flask. Determine the volume of water filling the flask by pouring into a 100 mL graduated cylinder. Use a dropper in the beginning to prevent spillage. Water level in the graduated cylinder should not be at 100 mL, but you should read it off as precisely as possible when it is almost filled to the 100 mL mark. It will take several steps to measure the volume of all water in the flask. Add all your readings to obtain the total volume of the flask. Record room temperature and pressure. Make sure to include their units.Explanation / Answer
1. Cover an erlenmeyer flasks of 250 mL with parafin and write down the mass. Do it by triplicate.
2. Put some globes on your hands, or use something to grab a piece of dry ice and cover it really thight with parafin. Do a lot af holes in the parafin so the CO2 gas can escape. and put it inside the erlenmeyer flask.
3. wait until the ice sublim, and let the flask to reach room temperature. Write down the mass again in this moment by triplicate. weight it until you see there is no big chances in the weight. and do it by three.
4. add water until the top of the flask.
5. use a 100 mL graduated cilinder to measure the total volume of water that you could put in the erlenmeyer flask. remember to fill the flask until the 100 mL mark. Do this measures the most exactly you can. Do it many times it requires so you can measured all the glass that was inside the erlenmeyer.
6 Do not forget to write down the temperature and the pressure in the enviroment and write it dow with its respective units.