It occurs when there is an absence of seed crystal or nucleus (nucleation points) for the formation of a crystal lattice structure by water molecules. It is found out that hot water would supercool lesser than cold water (i.e. hot water freezes at a higher temperature than cold water). Auerbach (1995) found out that that the most probable freezing temperature, Tf of hot water at 90oC was at 0oC - -2oC, with a probability of 0.41, Whereas Tf of cold water at 18oC was at -4oC to -6oC, with a probability of 0.56 However, the reason behind supercooling on the Mpemba Effect was not determined. In fact, theoretically, hot water should supercool less than cold water, due to the fact that hot water contains lesser amounts of dissolved gases than cold water as these gases were driven off in the process of heating the water.
12. The TLC data obtained is provided in a table below. The TLC data was conducted solely in a 9:1 hexane/ethyl acetate solvent solution as opposed to the 1:1 and pure hexane solution as well. This was due to the lack of time, but as explained in number 7, a very polar solvent (1:1 solution) or non-polar solvent (pure hexane) is not ideal when obtaining
This curve does not match exactly the figure 6 on the lab manual. It is steeper than the simple distillation but not as sharp as the fractional distillation. Some errors in the experiment that led to these results were the heat applied to the mixture was not constant. It had to be fluctuated as initially, the rate was too high but when the heat was set to low there was barely any distillate in the receiver. Throughout the experiment, there was a struggle to keep the heat stable which led to inaccurate data.
Since there is a 1:1 stoichiometry in the chemical reaction, as we know that for every one molecule of base that was needed to react with one molecule of acid. So the moles of bases and acids become same and as a result we can obtain equation which is given below to figure out unknown concentration of acid. C_acid*V_acid=C_base*V_base Finally, the obtained results from experiment compared with the theoretical values to sure from the punctuality of
The theoretical yield for Zinc Sulfide is 0.49 grams but the actual yield is 0.38 grams. So if 0.38 is divided by 0.49 and multiplied by 100 then the percent yield for Zinc Sulfide would be 77.6%. When it comes to Sodium Chloride, the theoretical yield is 0.58 grams and the actual yield is 0.45 grams. So when 0.45 grams is divided by 0.58 grams and multiplied by 100, the percent yield would be 77.5% of Sodium chloride. The actual yield is directly taken from the mass of the products in the experiment while the theoretical yield is determined by using stoichiometric calculations.
Then percent yield was calculated to be 67.57%. The isolation of less product resulted from using less amount of acetanilide than 0.07g at the beginning of the experiment. In addition, the melting point of the product was measured to be 164.8-168.50c, which is in the range of the normal melting point of 4-bromoacentailide, 165-1690c. This confirmed the formation of 4-bromoacetanilide from the bromination of acetanilide. From the bromination of 0.05g aniline, 0.156g of the product was collected.
That factor was whether or not the trial used a rock sample. If it did use a rock sample, the time it took to drain the water would have been longer because the rock blocked the water from being drained, and therefore, delayed the draining time. If you look in the table, you can see all of the control test values are lower than the sample test values. However, it’s unclear as to why the outliers were not in the expected range. The values might have been influenced by a possible experimental error.
The melting points for the acidic and neutral compounds were hence too low, and the melting point for the basic compound was too high. The errors in the acidic and neutral compounds can be explained by impurities in the crude product, along with the presence of the solvents, ethyl acetate and water, which disturbed the stability of the compounds, and led to lower melting points over a larger range. The abnormally high melting point of the base may have been observed due to improper separation of the acid and base solutions in the separation funnel. Some of the acidic compound may have entered the basic solution and reacted with the base to form a high melting point salt, making the melting point of the base appear abnormally high. The Mel-Temp was also turned on a high setting accidentally, so it is possible that the temperature rose too quickly to get a good reading of the melting
Acceptable criteria: % Assay should not vary by ±1%. 7.4.7. Specificity A solution of mixture of Amoxicillin trihydrate and its impurities was prepared by spiking of all three targetted impurities at a level of 0.01%. Acceptable criteria: Resolution of NLT 1.5 from primary peak 7. SYSTEM SUITABILITY THEORETICAL PLATES: A standard solution of 25 µg mL-1of Amoxicillin trihydrate (in triplicate) was prepared and same was injected, then the system suitability parameters were calculated.
Hence, Beaker 1 also cooled slower than Beaker 2. Comparing results from Part I and Part II demonstrates how Beaker 1 cooled faster in Part II when it contained GHG than in Part I. Additional outlier which could be related to the results is wobble of the beakers which occurred at some point while Part II was in realization. This outlier may had an impact in a way that it caused the temperature to drop. Outlier has a negative effect on the data and it generates fall out of the general