Determination of the molar volume of hydrogen gas Essay Example for Free

Determination of the molar volume of hydrogen gas Essay Introduction We are going to determine the molar volume of hydrogen gas by letting known amount of magnesium react with dilute hydrochloric acid and carefully collecting the gas formed. Materials Gas syringe Hydrochloric acid, 2-molar 8 cm of magnesium ribbon Ruler Emery cloth For details see instruction form Methods We connect the equipment according to the diagram and make sure we follow the instructions carefully, and then we weigh the 8 cm of magnesium ribbon and pour the HCl into the test tube. As we are ready to start the experiment we fold the mg ribbon on the hook and put the stopper into the test tube so that when we tilt the test tube the mg ribbon can easily fall into the acid. It is important to wait for the reaction to finish completely so that the equipment returns back to room temperature. For details see instruction form. Results: Measured weigh of 8 cm mg ribbon: 0.068 g (uncertainty is à ¯Ã‚ ¿Ã‚ ½ 0.0001) Room temperature: 21.9 à ¯Ã‚ ¿Ã‚ ½C (uncertainty is à ¯Ã‚ ¿Ã‚ ½ 0.1) Room pressure: 742.5 mmHg Vapour pressure of water: 19.587 and 19.827 Vapour pressure: 19.587 + 19.827 / 2 = 19.707 1.333 x 102 x (mmHg) = Pa Convert the room pressure in mmHg into Pa: 742.5 x 1.333 x 102 = 98975.25 Pa Convert the vapour pressure of water into Pa: 19707 x 1.333 x 102 = 2626.9431 p(H2O) = 2626.9431 Pa Room pressure (Pa) Vapour pressure of water (Pa) 98975.25 Pa 2626.9431 Pa = 96348.3069 Pa p(H2) = 96348.3069 Pa p(H2) + p(H2O) = p(room) 2626.9431 + 96348.3069 = 98975.25 p(room) Calculation of molar volume for hydrogen gas at 0 C and 1 atmosphere P1 x V1 / T1 = P2 + V2 / T2 1 atm = 1.013 x 105 P1 = 96348.3069 P2 = 1 atm = 101300 V1 = 70 cm3 (uncertainty is à ¯Ã‚ ¿Ã‚ ½1) V2 = 59cm3 (uncertainty is à ¯Ã‚ ¿Ã‚ ½0.5) T1 = 21.9 à ¯Ã‚ ¿Ã‚ ½C = 294.9 K (uncertainty is à ¯Ã‚ ¿Ã‚ ½1.3466 ) T2 = 0 à ¯Ã‚ ¿Ã‚ ½C = 273 K 96348.3069 x 70 x 1 / 294.9 = 101300 x 59 x 0.5 / 273 Conclusion Evaluation: Our conclusion is that the molar volume of hydrogen gas at 0 à ¯Ã‚ ¿Ã‚ ½C and 1 atmosphere is -. We reached the conclusion by first checking the room temperature and barometer pressure. Then we looked up the values for vapour pressure of water at the actual temperature from the Hand book of Chemistry and Physics. The full reference is: Chemistry for the IB diploloma G. Neuss. Oxford UP, 2001 p.28.