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Three major classes of chemical reactions
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Chemistry lab practical
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Alan Purves Hour 5 Javner Classifying Chemical Reactions Lab Summary Reaction #1 Type of reaction: Synthesis Balanced equation: 2Mg + O2 = 2MgO Observations: Once the magnesium was set on fire, it combined with oxygen and produced a very bright white light. The reaction left a white ashy powder on the tray. Reaction #2 Type of reaction: Single Replacement Balanced Equation: 2HCl + Mg = MgCl2 + H2 Observations: There was a fizz that occurred in the test tube which means a gas was produced. Also the mixture became warmer, and when putting the lit piece of wood in the tube, the flame went out immediately making a noise, which means that there was no oxygen Reaction #3 Reaction type: Decomposition Balanced equation: 2CaCO3 + 4HCl = 2CO2 + 2CaCl2
The procedure of the lab on day one was to get a ring stand and clamp, then put the substance in the test tube. Then put the test tube in the clamp and then get a Bunsen burner. After that put the Bunsen burner underneath the test tube to heat it. The procedure of the lab for day two was almost exactly the same, except the substances that were used were different. The
In Lavoisier’s Memoir in Combustion in General, the author emphasizes the importance of organizing experimental data to form new theories. Specifically, he encourages hypothesis testing and trial-and-error to better understand the laws of nature. Lavoisier apply these principles to his own theory by outlining the observations from combustion and calcification, and by hypothesizing the properities of “pure air” and “the matter of fire”.
The purpose of the experiment is to determine the ID of an unknown diprotic acid by establishing its pKa values. The first phase is to determine the unknown diprotic acid by titration, which is a technique where a solution of known concentration is used to determine the molecular weight. While the second phase involved seeing how much NaOH needed to standardize diprotic acid.
A precipitation reaction can occur when two ionic compounds react and produce an insoluble solid. A precipitate is the result of this reaction. This experiment demonstrates how different compounds, react with each other; specifically relating to the solubility of the compounds involved. The independent variable, will be the changing of the various chemical solutions that were mixed in order to produce different results. Conversely the dependent variable will be the result of the independent variable, these include the precipitates formed, and the changes that can be observed after the experiment has been conducted. The controlled variable will be the measurement of ten droplets per test tube.
A flame from a Bunsen burner was held to the Mg, and it ignited, giving off a brilliant white light. Looking directly into the light resulted in temporary blindness, which would explain the warning on the procedures that strongly suggested not looking directly into the light. After the flame had extinguished due to lack of fuel, the Mg had turned from a metallic strip to an off-white powder, which crumbled at the slightest irritation. The magnesium had bonded with the oxygen gas in the air from the energy that was applied to it and formed magnesium oxide. The type of reaction is a synthesis reaction, as is shown by this equation.
The experiment was to investigate what are the products of a chemical reaction, more specifically, what iron compound is formed. A chemical reaction is anything that has had a color change, the formation of a solid, bubble, or a temperature change. In an oxidation-reduction reaction, charges of molecules are going to change. The first balanced equation was Cu〖SO〗_4+Fe(s)→Fe〖SO〗_4+Cu. The second balanced equation was 2Cu〖SO〗_4+3Fe(s) →3〖Fe〗_2 (〖SO〗_4 )_3+Cu. Given the two different chemical formulas, the theoretical yield was found to determine how much copper would be left over after the reaction by using the balanced chemical equations and stoichiometry. With the iron being the limiting reagent, we knew that the excess of copper product
In this lab experiment, various solutions of different concentrations were created with Fe(NO3)3 (mL), KSCN (mL), and H2O (mL). When these chemicals were combined, a solution that was pale orange in color was created. These solutions were placed into a Colorimeter and their absorbance values were determined. Once these absorbance values were obtained, many calculations were done, including the Law of Mass Action (Keq = ([C]c x [D]d) / ([A]a x [B]b)) to determine the final answer of 159.7. This value is compared to the accepted Kc value of 133, revealing a percent error of around 20.08%.
The exothermic reaction observed in this procedure is as follows ; HCL(aq) + NaOH(aq) ➡ H2O(l) + NaCL(aq) + energy. The purpose of the lab was to determine the value of ∆H of the neutralization reaction above, then compare the data to that of the accepted ∆H value of neutralization to determine the accuracy and validity of our findings. A singular trend was observed and is as follows; the decrease of ∆H indicates a reaction is exothermic, a neutralization reaction results in a (-) value ∴ the (-) value collected was congruent with the trend above, proving our results have some legitimacy at the least.
In this lab, it was determined how the rate of an enzyme-catalyzed reaction is affected by physical factors such as enzyme concentration, temperature, and substrate concentration affect. The question of what factors influence enzyme activity can be answered by the results of peroxidase activity and its relation to temperature and whether or not hydroxylamine causes a reaction change with enzyme activity. An enzyme is a protein produced by a living organism that serves as a biological catalyst. A catalyst is a substance that speeds up the rate of a chemical reaction and does so by lowering the activation energy of a reaction. With that energy reactants are brought together so that products can be formed.
The purpose of our experiment is to figure out the empirical formula of magnesium and oxygen once they are reacted together. Putting the piece of magnesium in the crucible with the lid somewhat open, we induce heat to have the oxygen and magnesium chemically react. The Independent Variable is the elements used, Magnesium and Oxygen. The Dependent Variable is the mass of the elements.
...sen burner, the oxygen gives more energy to the electrons in the flame, causing the flame to heat up more and more. Therefore, the chemical reaction of methane gas reacting with oxygen to produce carbon dioxide and water vapor is given off by the Bunsen burner. We can now understand that the yellow flame contains heat as a cause of the oxygen that was a part of the reaction, but to make the flame hotter, the percentage of oxygen being fed to the Bunsen burner must increase.
Based on your experiments what is the formula of the colorless gas that is released when heating the malachite?
The investigation could have been improved by testing the temperature variable on the computer as the stop watch I used could not cope with the speed of the reaction. It would also have helped to test each concentration more than once to ensure that the results were true. When using the light sensor I should have covered the underside of the sensor with black material rather than sticking on paper as this could have let in some light. In addition I should have used an artificial source of light as the natural light in the room was constantly changing as clouds pass in front of the sun. I could also have used a burette to measure out the reactants although the measuring cylinder was quite accurate.
Magnesium metal is flammable. It burns with an intense white flame that is difficult to extinguish. Keep loose magnesium away from Bunsen burners until it is in a covered crucible. Sometimes the magnesium ignites in the course of the experiment. If it does, avoid looking at it as it could damage your eyes and let it burn itself out. You can then proceed with the experiment; the ignition will not alter your