Our result would have been clearer to observe if we centrifuged it long enough because we might have lost some of the precipitate while washing it since it was not centrifuged long enough. 4. Answer the post lab questions: a. Zn + I2 + H2O Zn(OH)2 + I2 b. Zn(OH)2 + CH3COOH Zn(O2CCH3)2 c. A side reaction is an unwanted chemical reaction taking place that diminishes the yield of the desired product. d. In the synthesis of Zinc iodide, acetic acid was used because the aim of the experiment was to derive Zinc iodide. If we used water instead of acetic acid then zinc would have reacted with water and become Zinc hydroxide which would hinder our purpose.
They are used to speed up the reaction rates by providing an alternative reaction pathway of lower activation energy, which is the minimum energy that requires for reactions occur. Catalysts take part in a reaction (chemical involved), but they do not undergo any changes in chemical reaction. (Farabee, 2001) Enzymes are proteins made of a combination of different amino acids. Therefore, the enzymes may be lost
Online General Chemistry Titration of Acetic Acid in Vinegar Lab Manual pp158-167 When performing step 9 you want to remove all the NaOH from the beaker before adding acid (vinegar) to the beaker. If you do not remove the NaOH, it will react with the acid in the vinegar prior to starting the titration, making the vinegar appear less acidic than it really is. The next lab lists white vinegar as provided by the student. This one asks for brand and label information, yet implies the vinegar is provided by LabPaq. Results Sheet, Experiment 13 Brand of Vinegar used:________________ Acetic Acid % from bottle label_____________ | Initial NaOH Reading(estimate to 0.1 mL) | Final NaOH Reading(estimate to 0.1 mL) | Volume NaOH used(Final – Initial) | Trial 1 | 9.5 | 1.3 | 8.2 | Trial 2 | 9.6 | 1.4 | 8.2 | Trial 3 | 9.7 | 1.4 | 8.3 | Average Volume of NaOH used | 8.2 | Calculations: Normality of the acetic acid: .82 Mass of acetic acid: 49.2 % acetic acid (divide the grams, above, by the volume you used to get g/L): 4.92 Answer questions A-G in the lab manual: A.
Analysis and Interpretation Experiment 1 Aim 1 – How changing the concentration of I- ions affected the rate of reaction. This was the first reaction I conducted and I did this by keeping everything else constant whilst only changing the concentration of the potassium Iodide. At first I was due to keep the concentration of KI at 1M. However I found that the reaction was happening way to fast. As soon as I added the reactants together it would immediately turn dark blue.
DETERMINING THE PROPERTIES OF AN ENZYME I. Abstract Enzymes are responsible for the speed at which chemical reactions they are involved in take place. This experiment determines the effects that concentration, temperature, pH, and boiling have on an enzyme’s ability to perform its work. It is hypothesized that none of these variables will have any effect on the activity of enzymes and these hypotheses are tested using dye-coupled reactions to determine the rate at which peroxidase converts H2O2 into water (H2O) and oxygen (O2). Each hypothesis is subsequently rejected as data suggests that concentration, temperature, pH, and boiling all have an effect on enzyme activity. II.
In the case of pollution and carbon emissions, it is very hard to actually measure the level of carbon emissions being produced from a company. And even if you can it will be very costly, which means there is an opportunity cost of implimenting the law of how much carbon emissions can be produced. Realistically, all regulation can hope to achieve is a reduction in environmental damage and a movement towards the optimum level of output. A second difficulty with regulation is that the government must have the correct information, and therefore know the optimum level of output. This requires the perfect information which is rarely even achieved.
43________________________________________________________________ An electrolyte is a an ionic compound that breaks apart into positive and negative ions in a solution. The doctor was so concerned with the amount of electrolytes in eugene’s body because Electrolytes are one things that help the heart contract and relax and can lead to cardiac arrhythmia, which is the most common electrolyte deficiency. And when you are drinking your heart rate rises and that’s where the dangerous part come on. And if he is low on electrolytes, specifically sodium, the they can’t correct it quickly or it could cause an abnormal flow of water in or out of the cells which in turn could cause brain damage. If Eugene’s blood PH is really low than administering sodium bicarbonate (NaHCO3) will help him get back to the range of 7.35 - 7.45.
(h) "Hard" water contains a high concentration of calcium ions. Suggest a way to make hard water "softer: Answers: a) It could have been improved if the experimental design said " you have to place seven different nitrates in three different sodium solutions to see if a reaction occur." b) With my evidence silver nitrate was the would the cation that would make most of the anions create a precipitate. c) Chlorine can selectively remove silver ions from a solution because silver has a positive 1 charge and chlorine has a negative 1 charge so when they react it is a perfect
The unknown samples are strontium chloride and copper chloride. Some of the errors that might’ve occurred during our experiment could’ve been due to the fact that we didn’t have much time. Therefore, we rushed through the experiment and might’ve not washed the spatula properly before dipping it into a new substance. Due to this, the color of the flames emitted could vary and not be accurate because the different substances could’ve mixed. Lack of equipment could’ve been one of factors that contributed to our errors.
Because we didn’t count the proper number of significant figures in the volume we had too many when we went to calculate the density. Conclusion: In this experiment we were supposed to be able to identify unknown substances using physical properties. We were successful in understanding how the use of physical properties better helps when identifying various unknown substances. Because of this experiment I learned how to take weight calculate volume density solubility and specific gravity. We were able to determine that the unknown substance was methyl by using its boiling point and other physical characteristics.