Thursday 9/29/11 3:00pm Michaela Howard Partner: Craig Delancy Separation of a Mixture Containing Calcium Carbonate and Naphthalene Objective: Finding a method to successfully separate a mixture of calcium carbonate and naphthalene. Properties to be considered: Calcium Carbonate Naphthalene Solubility in water slightly insoluble Solubility in ethanol insoluble partially Melting point 825 degrees C 80. 2 degrees C Boiling point decomposes 218 degrees C Procedure: Subliming the mixture seemed to be the most practical solution due to the information given in lab by the instructor of the calcium carbonate and the naphthalene.
Their properties of solubility with water or ethanol was either slightly soluble or insoluble, making extraction by solubility a definite no with using this experiment to separate the mixture. The mixture was made by combining 0. 511g of naphthalene with 0. 350 g of calcium carbonate. It was then placed into a mortar and ground up into a fine powder. Once the mixture was ground up, the sample was placed into a fairly large beaker (80 mL). Using the sublime approach to separate, the hardest task was finding the right height of the ring stand away from the flame and finding the right temperature the flame gave off.
Also making sure the flame of the bunsen burner circulated the outside portions of the beaker so that it wouldn’t break the glass, balancing out the temperature instead of it being in one spot. Placing a watch glass on top of the beaker, with ice placed upon top of that, the mixture was heated until a reaction took place, resulting in small crystals began forming on the sides of the beaker with some on top as well. This was an indication that a smaller beaker was to be used next experiment.
However, after the mixture was separated, the beaker was then left in the drawer of the lab for week to cool off at room temperature. The watch glass and the beaker were then scraped for the remaining residue of the naphthalene and the calcium carbonate was also removed, then both were weighed. However most of the naphthalene crystals attached to the watch glass had fallen off and made it almost impossible to separate the two, which is why the weighed amount of each was not entirely accurate. So instead of getting the percentage of the remaining, the decision was made to just redo the experiment.
Using the same separation technique, only with a smaller beaker (50ml), the mixture was ground up and then weighed, with calcium carbonate being 1. 495g and naphthalene being 0. 873g. Once subliming took place, the naphthalene crystals started to form directly on the bottom of the watch glass instead of the sides of the beaker, which was the indication that the beaker was the correct size. Once the mixture was completely separated and the beaker cooled off to room temperature; the beaker and watch glass was scraped for the remaining residue, and after which they were weighed.
Data and Calculations: Calculation of Grams of Components in Mixture: Before Sublimation 18. 462g- Watch glass 0. 645g- Filter paper 0. 249g- Naphthalene with filter paper 0. 383g- Calcium carbonate with filter paper 28. 603g- Beaker weight (50mL) After Sublimation 18. 462g- Watch glass 19. 448g- Naphthalene weighed with watch glass 30. 109- Calcium carbonate weighed with watch glass Remaining Naphthalene on Watch Glass Calcium Carbonate in Beaker 19. 448naphthalene 30. 109calcium carbonate – 18. 462watch glass – 28. 603beaker 0. 86naphthalene 1. 506calcium carbonate End Results Naphthalene Calcium Carbonate 0. 873g(original weight) 1. 495g(original weight) 0. 986g(after sublimation) 1. 506g(after sublimation) % of naphthalene recovered= 0. 986g naph. recovered 0. 873g naph. in mixture X 100 = 112. 93% % of calcium carbonate recovered= 1. 506g cal. carb. recovered 1. 495g cal. carb. in mixture X 100 = 100. 74% Conclusions: Separation of the components by sublimation turned out to be successful with recovering both naphthalene and calcium carbonate.
With percentage rate of ~100% recovery of calcium carbonate and ~112% of naphthalene. With using a smaller beaker, the recovery rate and accuracy of obtaining the correct components from the beaker and watch glass was much easier compared to that of a larger beaker. The percent recovery in the larger beaker would not have been accurate due to the fallen crystals, and was no longer separated. With future experimentation, the components could be crushed separately in the mortar and pestle instead of being crushed together, so that some of the sample would not be lost during the combination.
Cite this Separation of a Mixture Containing Calcium Carbonate and Naphthalene
Separation of a Mixture Containing Calcium Carbonate and Naphthalene. (2019, May 01). Retrieved from https://graduateway.com/separation-of-a-mixture-containing-calcium-carbonate-and-naphthalene/