The purpose of the lab was to determine the molecular mass of Butane, and this was done by using the ideal gas law (PV=nRT). The materials used were: match, funnel, bucket, cylinder, thermometer, lighter, scale, and a wooden flynt. These materials are used to help collect and test the Butane gas. Butane gas was used because it is ideal at standard temperature and pressure.
Procedure: 1. Rinse bucket and fill three fourths full. 2. Rinse all glassware. 3. Place thermometer in bucket. 4. Record P= 760.4mm of Hg, 1.03 atm. 5. Record temperature. 22 C o 295 oK. 6. Weigh dried lighter 13.5 gms (before) and 13.4 grams (after) then record loss of gas after completing the experiment .1 gms(subtract before and after weights) 7. Next, put the cylinder emerged in the bucket without any air in it. Then put the funnel in the bottom and put the lighter up in the funnel and continuously strike it till there is atleast 70 ml of gas in the tube. 8. Test gas by lighting a match and putting it in the cylinder. Quickly take the cylinder out of the water and place the lit flynt up in the cylinder. 9. Rinse all materials 10. Record Vapor pressure correction 19.8 torr.
Results: After completing the experiment, PV=nRT was used. This was used to find the molar mass of Butane. After working out the equation V=nRT, the volume was determined. In liters the answer was .0399, but it is needed in milliliters so the decimal place is moved to the right 3 places to come up with 39.9ml as the volume calculated. The volume is calculated by plugging the correct numbers into the equation. In order to find the volume, the number of moles had to be calculated. The number of moles is .0017 moles. Moles in the experiment can be represented by the letter n. The “R” in the experiment is .082, and lastly the T is the temperature in Kelvin, which is 295o. Conclusion:
The percent of error in the experiment was 85%, and the percent yield was 185%. To improve the lab, when measuring the mass of the lighter in the beginning, it would be more accurate to take the decimal place out at least 3 places each time measuring. Also while doing the experiment, to make sure there aren’t any air bubbles in the cylinder when putting the lighter in it. Lastly to improve, when measuring the lighter, make sure it is completely dry.