The substitution reaction was successful but not fully effective. 19. If the data was inconclusive, then comparing various compounds and the unknown based on physical characteristics would be the first step, titrations would also be a good method. 20. To get a better yield, redoing the experiment would require careful attention in the recrystallization steps: amount of solvent used, how hot solvent is, if the mixture cools to room temperature before placing it in an ice
One error that could have affected the percent yield is not filtering out all of the liquid from the filter paper in the funnel before setting it off to dry. This would have increased the final mass of the solid, not making it accurate. To stop this from happening again, the liquid could be drained more thoroughly until it fully stops dripping into the Erlenmeyer flask. Another error that could have affected the percent yield is the amount of trials performed. This would have made the results less accurate and made any errors change the final results even more.
The density of magnesium is 1.740g/cm3 which means the metal will sink in water but it still a very light metal. Chemical properties Magnesium is a very reactive metal. The surface of magnesium metal is covered with a layer of oxide which is very thin to protect the metal from attacks by air. When magnesium reacts with oxygen it gives out a bright white light which should be looked at directly. How magnesium impacts the society Magnesium has a very good positive effect on the society.
Pure tungsten oxide is WO 3 and yellow. Further heat under a hydrogen atmosphere in high nickel boats reduces the oxide to tungsten metal powder "W". In the reducing operation the grain size of the tungsten powder is carefully controlled by controlling these
The technology can also clean water from high concentrated salt effectively (Nield, 2015, p.2). According to El-Shafi, as cited by Danise (2015, p.1), no electricity is needed if we use pervaporation. C. Disadvantages Despite the good advantages pervaporation provides, it contains some disadvantages. According to Nield (2015, p.2), there is a problem with pervporation and that is the production of water waste during the process. The membranes used in pervaporation might not be able to perform very effeciently (Nield, 2015, p.2).
If only one reactant is increased, then the chemical reaction will only produce a certain amount of products after the limiting reagent is used up, and in this experiment, the most mass the reaction could produce was 0.4 grams. Although we kept adding calcium chloride, not adding sodium hydroxide in the same proportions will not yield more product, which is the main goal in conducting this lab. We should have seen a plateau at 0.4 grams to show that the limiting reagent inhibited further Ca(OH)2 production, but we made several mistakes in our experiment, which made the data unusable to conclude. Once again, the data is polluted, so these number are not accurate, but it is the data our group has to work with. The theoretical yield should have been more than the actual yield, and the percentages should have been less than 100.
The melting point of the pure ASA crystals were calculated in order to calculate of absorbance. Iron (III) salicylate dianion must contain the acidified solution Fe3+ in order to measure the absorbance values. The level of the impurity can
To calculate the percentage of Cu, we divided the final mass of the penny 0.09 and the initial mass of 2.47 and multiplied by 100. To calculate the percentage of Zn, we divided the final mass of the penny 2.38 and the initial mass of 2.47 and multiplied by 100. During the experiment the hydrochloric acid donated its hydrogen ions in the reaction and then the chloride ions reacted with the zinc ions in the solution. Thus, the zinc dissolved in the highly acidic solution which was caused by the high concentration of H2 ions. Hydrogen gas was generated during the reaction which was seen when bubbles were formed as the penny was dissolved into the beaker.
This helped us to verify Newton’s second Law of Motion. I believe our “true” objective in this lab was met sufficiently, that was to understand the implications of Newton’s second law. However, the data we gathered does not reflect the theoretical value of gravity greatly as we were not able to get a single calculation of G that was under 10m/s^2. Fortunately, our main sources of error were human errors and that does not conclude the second law is false. Therefore, I think errors are
(a) Formation of calcium chloride (b) Formation of magnesium oxide (c ) formation of bonds in sodium fluoride Checking Up: 2 1. For each of the following ionic bonds: Sodium + Chlorine, Magnesium + Iodine, Sodium + Oxygen, Calcium + Chlorine and Aluminium + Chlorine a) Write the symbols for each element. b) Draw a Lewis Dot structure for the valence shell of each element. c) Draw an arrow (or more if needed) to show the transfer of electrons to the new element. d) Write the resulting chemical formula.
after we added NH3 to the solution, a precipitate formed for nickel. we mixed everything together which formed an orange specks of precipitate formed. we tested calcium and in our unknown we did have calcium. precipitate formed when we added K2C2O and NH3 to the supernate. Then, we did flame test and we see a color changed to see if calcium appeared which it
This lab’s end result was to correctly identify each unknown solution using prior knowledge of chemical properties and the results of the first experiment conducted. Unknown solution D was the only colored solution, being blue while the others were clear. This made it easy to then match D up to Copper Sulfate because of its color. As unknown A and B were added together, lots of gaseous bubbles formed and revealed the fact that that reaction was the reaction between Hydrochloric Acid and Sodium Carbonate because it was the only reaction that produced a gas release. Unknown A and C produced the only yellow, brown precipitate just as the reaction between Sodium Carbonate and Silver Nitrate had previously.
Here, it can be seen that the chlorine anion that was a part of the hydrochloric acid is transferred to the pure magnesium, leaving behind hydrogen. Double-replacement reactions are yet another type of chemical reactions. A double-replacement reaction also involves the transfer of anions. However, unlike a single-replacement reaction, a double-replacement reaction has two anions being intrechanged. An example of this type of reaction would be the combination of hydrochloric acid and sodium hydroxide to form water and sodium chloride: HCl + NaOH --> H2O +
The heat test was was the most important because it can determine what the powder would smell, sound, and look during the heat test. C and D were the only ones that were chemical reactions because they were showing sign of chemicals. It was a need to retest, so we can know it is reliable and accurate. To avoid contamination, we would open one at a time and use one spoon for each container. I wouldn 't do anything new to improve this lab because we did exactly what the guide paper told us to do.