Chemitry Lab - Molar Volume of a Gas
Extracts from this document...
Introduction
Introduction: In this lab I am going to find out the volume of one mole of hydrogen gas at room temperature and atmospheric pressure. The room pressure only slightly differs from the standard, but can be taken into consideration when calculating the results. The molar volume is 22.41 liters per mole at STP (Standard pressure), in other words, at zero degrees centigrade. Figure 3.1 (the experiment set up) Procedure: 1. Set up all equipment. 2. Cut a piece of Magnesium ribbon about 20cm in length. 3. Calculate the weight of the ribbon from the weight of a 1 m long ribbon. 4. Measure 1.0 M Hydrochloric acid to a volume of 25-30ml. 5. Pour the HCl to the reaction flask. 6. Add the Mg ribbon to the reaction flask and secure the mouth of the flask as fast as possible with a hose. Make sure that the hydrogen gas cannot escape from the flask. 7. Follow the temperature 8. Collect the gas until no further reaction is observed in the reaction flask. 9. Carefully remove the gas collection flask so that no gas escapes from the flask. 10. Light the gas. 11. Determine the volume of the gas. ...read more.
Middle
* After the reaction, when lighting the hydrogen gas, collection beaker made a popping sound but the reaction flask actually burned and formed a thin flame. * The flame from the reaction flask gave out a lot of heat, which was not noticed when lighting the gas in the collection flask. Figure 3.2 Time (min) Temperature (C) 0 22 1 27 2 26 3 25 4 25 5 25.5 6 26 7 26 8 26 9 26 10 26 11 26 12 26 13 25.5 14 25.5 15 25 Figure 3.3 Calculations: 1.000m � 1mm of Mg ribbon weights 1.06 g �0.005g 25.8cm �1mm Mg ribbon used weight = 0.27348g 1.06g ? 25.8cm = 0.27348 ? 0.96% (0.003g) 100 30ml � 1ml (3.3%) of HCl m(Mg)=0.273g M(Mg)=24.31 n=0.273 = 0.011 n(H2) 24.31 Molar volume at the conditions in the room? molar volume= liters mol V(m)= 0.292l = 26.545 l/mol 0.011moles Correction for temperature 26.545 l at 294 K ? l at 273 K pV=nRT V1=V2 T1 T2 24.545 l/mol = X X = 22.79 l/mol at room temperature 294 K 273 K Correction for pressure P1 =750 TORR P2= 760 TORR 22.79 = X X= 22.5 l/mol 760 750 22.49 - 22.41 = 0.36% error 22.49 Theoretical = 22.5 l/mol Vm= 22.41 0.36 % error The molar volume was 0.36% too large. ...read more.
Conclusion
The experimental value turned out unexpectably very small. 0.36% error in the experiment seems very small, unless there has been some unnoticed mistakes that have influenced the experimental value. The theoretical value is 22.5 l/mol. Temperature changes during the experiment turned out some interesting results, for the temperature seems to start falling soon after the chemical reaction has ended, yet it begins to rise a little after a few minutes and stays constant for a long time before starting to fall (figure 3.2). From the information gained during this experiment, it is difficult to state why this happened; therefore, some extra research should take place if performing the experiment again. Improved investigation: For further investigation, temperature should be measured for longer than 15 minutes in order to find out the rate the temperature is going to fall in a closed flask. The distance between water surface in the container and the surface in the flask should also be measured. For more accurate results, factors such as air and water vapour in the flask should be taken into consideration when calculating the final values. Advisable would be to do some research on why the temperature changed the way it did in this experiment. ?? ?? ?? ?? The molar volume of hydrogen gas 20.10.2009 ...read more.
The above preview is unformatted text
This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.
Found what you're looking for?
- Start learning 29% faster today
- 150,000+ documents available
- Just £6.99 a month
