Magnesium thread was reacted with Hydrochloric acid in three different experiments to find the charge on a metal ion. After running multiple trials in the three different processs. the Crystallization method proved to be the best method for finding the charge of the metal ion by utilizing mole to mole ratio. Introduction
The aim of the Get Charged Up lab was to find the charge on a metal ion responding with HCl by finding the mole ratio in a reaction by finding the sum of extra reactant. sum of merchandise. and sum of H gas produced every bit good as happening the best research method to find the charge. To carry through this. three different methods were used. Titration was used to respond NaOH with HCl to find the sum of H+ left over after the reaction is complete. Crystallization was used to find the sum of MgClâ‚‚ made after the reaction is done.
Both of these methods allowed us to cipher the sum of H+ responding with the sum of Mg. The gas jurisprudence method and the Ideal Gas Law was besides used to find the mole ratio of Mg metal to hydrochloric acid by mensurating the sum of H gas based on the force per unit area and temperature alterations during the reaction. With the consequences from each process. graphs were constructed and the most accurate and precise method was discernable. It is predicted that the titration method will be the most consequence method of discouraging a charge on a metal ion because about all of the experiment done with titration is done by the experimenter and is the reasonably easiest method. A titration is a method of analysis that will let you to find the precise end point of a reaction and therefore the precise measure of reactant in the titration flask. Because of this preciseness. the titration method will be best for finding the charge of a metal ion because it is the most effectual procedure. Method
Three different methods were used to find which was the most accurate and precise method for finding the charge on a metal ion responding with HCl. The first method used was the titration method. Titration is the finding of an sum of a substance by responding the substance with a known sum of another substance. In this lab. NaOH was used to respond with HCl to find the sum of H+ left over after the reaction was complete. Magnesium thread was cut into six different multitudes and placed in six different beakers and allowed to respond with 10. 0 milliliter of HCl. An index was added to each beaker to find when there is still H+ nowadays in the solution. After the reaction was completed. each beaker was titrated with Na hydrated oxide ( NaOH ) until an terminal point was reached ( colour alteration from the index ) .
Using the mass of Mg. molar mass of Mg. moles of NaOH. and the terminal point volume. the moles of H+ responding with Mg can be calculated. ( The existent process can be found on pages 39-41 of the lab manual ) The 2nd method used to find the mole ratio between Mg and HCl will be to bring forth the metal chloride as a solid so it can be weighed. This is called crystallisation. Six different beakers were weighed and a piece of Mg thread was cut to assorted multitudes ( see page 42 of the lab manual ) and placed into each beaker. Using a buret. 10. 0 milliliter of HCl was added to each beaker to respond along with an index ( phenolphthalein ) and each was allowed to travel to completion. After completion. each beaker was placed on a hot home base and brought to a soft furuncle. Solutions were boiled until the H2O and extra HCl had evaporated. The mass of each merchandise ( beaker and crystals ) was recorded. At the terminal of the process. moles of Mg used in each test was calculated along with the Moles of Cl in the salt for each test. ( The existent process can be found on pages 42-44 of the lab manual )
The Gas Law method was the 3rd method used to find the sum of H produced when Mg metal is reacted with hydrochloric acid. About 0. 025 g of Mg thread was placed in a flask after entering its mass. About 80 milliliters of HCl was obtained and assorted with phenolphthalein. Using a LabQuest unit and Gas Pressure Sensor kit. the HCl mixture was added to the flask with the Mg thread and allowed to respond. When reaction was complete. the alteration of temperature and gas was recorded. This process was repeated for different multitudes of Mg thread ( masses found on page 89 of the lab manual ) . After the accomplished process. moles of Hâ‚‚ produced in each test were calculated. ( The existent process can be found on pages 87-89 of the lab manual )
After each process. a graph was created for each set of informations to compare and contrast consequences. It should be noted that non all supplies are listed here every bit precisely what is needed to execute each method but a complete list can be found in the lab manual predating each experiment. Pay utmost cautiousness to the handling of HCl as it can do acerb Burnss on your tegument and take colour from your vesture. Should you acquire any on you or your apparels. rinse with soap and H2O. Besides. when utilizing flask with thermocouple. it will be top heavy and can easy tumble over and interrupt. A concluding safeguard. H gas is being produced during the gas jurisprudence method and hence no unfastened fires in the research lab during that part of the experiment. Consequences
The titration method had the best correlativity coefficient of the entered information. The crystallisation method had the most accurate incline for the determined substances. The ideal gas jurisprudence method was close to comparing to the titration method but some informations points were a small far off from the tendency line. All three graphs had a positive correlativity in footings of the ten and Y relationship. Table 1. Crystallization Method
There is a positive correlativity between the moles of Mg compared to Moles of Cl in salt. The correlativity coefficient of 7964 relates to the truth of the informations and the incline of the line ( 1. 981x ) relates to the mole ratio between the two substances.
Table 2. Ideal Gas Law Method
There is a positive correlativity between the moles of Mg compared to Moles of H2 produced. The correlativity coefficient of. 9956 relates to the truth of the informations and the incline of the line ( 0. 8167x ) relates to the mole ratio between the two substances. Table 3. Titration Method
There is a positive correlativity between the moles of Mg compared to Moles of H+ responding with Mg. The correlativity coefficient of. 9999 relates to the truth of the informations and the incline of the line ( 1. 7923x ) relates to the mole ratio between the two substances. Discussion
The best method was the crystallisation method for finding the charge on a metal ion. The best method is the most accurate method. This was determined by looking at the correlativity coefficient. y-intercept. and incline of the line on the several graph and seeing the tendency of positive correlativity. The crystallisation method had a incline closest to what it was supposed to be ( 1. 981 compared to 2. 000 ) giving up that this method was the most accurate at finding the charge on a metal ion because we knew the mole ratio needed to be 2:1.
Mg ( s ) + 2H+ ( aq ) – & gt ; MgÂ²+ ( aq ) + Hâ‚‚ ( g )
These consequences disproved my anticipation in that I believed the titration method to be the most accurate method at finding the charge of a metal ion. When believing about my anticipation. I ruled out crystallisation because I did non believe it would be the most accurate due to the different sorts of mistakes that could perchance happen in comparing to titration or the gas jurisprudence method. Although crystallisation proved to be the most accurate method. it was non the most precise. The most precise method was the titration method because its correlativity coefficient was the closest to 1. 000 ( . 9999 ) . This tells us that the informations collected was all within about the same scope. The deficiency of crystallisation non being the most precise or the deficiency of the other two methods being such can be attributed to possible mistake in the research lab whether it is method mistake or measuring mistake.
One of the largest mistakes that could hold occurred with the gas jurisprudence method was that the equipment was non the best. There were frequent leaks in the thermocouple every bit good as the turncock and syringe. Both of these mistakes could be prevented in the hereafter with better equipment. holding lubricating oil to basically “lock-in” the stopper. or running several trials to guarantee that the equipment you were utilizing was non defective. An mistake that occurred with the titration method was that of over-titration of the solution.
By over-titrating. one can non be definite at the end point volume which was used to find the moles of NaOH. Not holding the right moles of NaOH you would non hold the right moles of H+ responding with Mg hence doing your consequences inaccurate and non holding the right mole ratio to find the charge of the metal ion. To better this for the following lab. one could pattern titrating different volumes of H2O until comfy with titration. The mistake that could hold contributed to all of the three methods of metal ion charge finding was that of the reaction of the Mg thread with the HCl. By non leting the reaction of the two to travel to completion before adding another substance could hold skewed the consequences of each lab.
For future labs including Mg responding with HCl. experimenters need to do certain that the reaction has gone to completion each clip they are reacted before adding another substance to the mixture. By making this. you would forestall mistakes in end points. Further research could be done utilizing the gas jurisprudence method as the devices and equipment we used were non the best quality. By bettering quality. we could better our consequences which may supply an even better finding of a charge of a metal ion by finding the moles of Hâ‚‚ produced. Besides. one time better equipment is acquired. multiple trials should be done to find the moles of Hâ‚‚ produced versus the four trials that we ran. Decision
This study has discussed the development of a charge on a metal ion based on three different independent experiments. The aims of this lab were to happen the necessary experiment to hold the HCl react with Mg to find the charge of a metal ion. Both aims were met. By maintaining path of the mass of crystals produced by the crystallisation method and ciphering the about of moles of Mg and moles of Cl in salt. by comparing the mole ratio of 2:1. the charge of the metal ion was determined. It was a surprising find to see that the crystallisation method was the most accurate method because of the higher possible mistake.
Malina. Eric. 2013. General Chemistry Lab Manual.