Charles Law Lab updated

Charles’ Law and Absolute Zero Introduction Charles’s law states that the volume of the given amount of a gas is directly proportional to the absolute temperature when the pressure and the number of moles of the gas are held constant. The purpose of the lab is to verify Charles’ law using the volume-temperature relationship. The volume of the cylinder is directly related to length so if length changes, it means the volume changes. The length will also be changed when the temperature changes. This gives the clue that volume and temperature are directly proportional to each other. Using those relationships, absolute zero temperature will be found. Materials • 400 ml beaker • Mercury tube • Cork • Rubber bands • Tap water. • Thermometer • Wire gauze • Tripod stand • Clamp stand • Ring stand Procedure Following steps must be used to perform the experiment: 1. Take a 400 ml beaker and fill it with tap water. Heat the beaker to 50-55 0 C and note down the initial temperature reading on the thermometer. 2. Attach the rubber bands to the top and bottom of the thermometer and cork to the top of the thermometer. 3. Place the beaker on the tripod stand and set up the ring stand along with it.

4. Obtain a sample tube and strap tube and thermometer to the plastic ruler. It will help to measure the positions of the mercury plugs during the lab experiment. 5. Lower the tube into the beaker of pe-heated hot water. Make sure that the water level covers the upper mercury plug, otherwise add more water. 6. Wait for two minutes and record the changes in the temperature and location of the mercury surfaces. a. The difference between the initial and final length must be taken to get the exact change in the length. 7. Add small pieces of ice to decrease the temperature of water and stir it carefully. When the equilibrium is established, note down the new temperature and changes in the location of the mercury plug in the data table. 8. Repeat steps 6 and 7 at least ten times to get the data set of 10 values. 9. Remove the tube from set-up and the tube containing the mercury in a safe position in the hood. Data Table Temperature ( 0 C) Top Plug position (mm) Bottom plug (mm) Length (mm) 50 79 33 46 46 78 32 46 43 77 31 46 38 76 33 43 30 75 32 43 21 74 31 43 10 73 31 42 3 70 31 39

Conclusion The objective of the lab report is to check the relationship between the volume and absolute temperature. Using the relationship between the length and volume, it is proved that volume of the gas is directly proportional to absolute temperature. The results can be seen using the graph and the trendline equation which has a positive slope indicating that two quantities are directly related. This trendline equation also helps to find the value of absolute zero temperature and that comes out to be -302.45 0 C and the percentage error of around 10.8% which is nearly in the acceptable range. The theoretical value of the absolute zero temperature is -273 0 C. The reasons for the difference in the actual and the calculated value are errors when noting the temperature and length changes. The small error may cause the results to differ from the actual results. The results can be improved by taking care when noting the temperature and length changes.