Stoichiometry is a method used in chemistry that involves using relationships between reactants and products in a chemical reaction, to determine a desired quantitative data. The purpose of the lab was to devise a method to determine the percent composition of NaHCO3 in an unknown mixture of compounds NaHCO3 and Na2CO. Heating the mixture of these two compounds will cause a decomposition reaction. Solid NaHCO3 chemically decomposes into gaseous carbon dioxide and water, via the following reaction: 2NaHCO3(s) Na2CO3(s) + H2O(g) + CO2(g). The decomposition reaction was performed in a crucible and heated with a Bunsen burner. The study of Green Chemistry emphasizes the reduction of hazards to human health and the larger environment, as well as …show more content…
The decomposition of NaHCO3 is an example of Prevention within Green Chemistry principles because all solid waste in this experiment is collected and used again. The only gaseous wastes generated by the reaction in the experiment are carbon dioxide and water, which are benign (Lab 3). The decomposition reaction of NaHCO3, generates virtually no waste, therefore less hazardous chemical syntheses. The byproducts of the reaction are gaseous CO2 and H2O which possess little or no toxicity to human health and the environment, because of the amounts released in this experiment. (Lab 3). 3. In this experiment, the percent yield was 90%. This number implies that there was little error in this experiment. However, this result could have been caused by certain external factors. Firstly, because the NaHCO3 compound was not stored in a sealed container, therefore dust particles could have changed the results, and making the product impure. Also, there are uncertainties associated with the instruments used in this experiment. This, if the products were measured slightly more than should be, this could have affected the concentrations of the solutions, and therefore causing a larger
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Results The data obtained from the experiment had undergone statistical analysis using t-tests and the results were recorded in Figure 1.0 and Figure 1.1 above. According to the data obtained in Figure 1.0, the p-value is less than 0.05 in all 5 treatment solutions. It is also shown intensity Figure 1.0, the calculated t-value of each concentration of NaHCO3 in each treatment is greater than the critical t-value.
The Wittig reaction is valuable reaction. It has unique properties that allows for a carbon=carbon double bond to form from where a C=O double bond used to be located. Creating additional C=C double bonds is valuable due to its use in synthesis. The Wittig reaction will allow the synthesis of Stilbene (E and Z) from a Benzaldehyde (Ketcha, 141).
1. 150 ml of boiled water was poured into each of the three beakers labeled A, B, C. 2. Five tea bags were soaked for the time given by the manufacturer (two minutes) , in beaker A (Control). The teabags were immediately removed after the time elapsed. 3.
The results do not support the hypothesis that a higher surface area to volume ratio would result in sulphuric acid being diffused into the agar cubes in the shortest amount of time. This is evident in the results as the exact opposite to what was predicted occurred. Instead of the smallest cube with the largest surface area to volume ratio of 1cm3 having the quickest diffusion rate, it conversely took the longest at 0.092 cm3 per second, whilst the 2cm3 cube with 0.0384 cm3 per second took the least amount of time. This directly refutes the hypothesis. There was also no consistent trend evident in the results.
As seen in table 1, the theoretical yield was .712 g of C_17 H_19 NO_3. The % yield of this experiment was 7.51 % of C_17 H_19 NO_3. . This low yield can be explained from a poor recrystallization technique combined with potential contamination. Throughout the experiment, the mixture changed color from green, orange, to yellowish lime, and eventually clear.
Properties of Ionic and Covalent Substances Lab Report Introduction The purpose of this lab was to determine which of the following substances: wax, sugar, and salt, are an ionic compound and which are a covalent compound. In order to accurately digest the experiments results, research of definitions of each relating led to the following information: ionic compounds are positive and negatively charged ions that experience attraction to each other and pull together in a cluster of ionic bonds; they are the strongest compound, are separated in high temperatures, and can be separated by polar water molecules. A covalent compound forms when two or more nonmetal atoms share valence electrons; covalent compounds are also
The actual data is the result on our experiment vs theoretical, which is based on the calculations above. I have also learned to pay more attention to draining out all of the product completely before continuing to test the experiment, as any small drop of contaminant can veer our results into a different
Properties of Ionic and Covalent Substances Lab Report Introduction The purpose of this lab was to determine which of the following substances: wax, sugar, and salt, are an ionic compound and which are a covalent compound. In order to accurately digest the experiments results, definitions of each relating factor were researched, leading to the following information: ionic compounds are positive and negatively charged ions that experience attraction to each other and pull together in a cluster of ionic bonds; they are the strongest compound, are separated in high temperatures, and can be separated by polar water molecules. A covalent compound is formed when two or more nonmetal atoms share valence electrons; covalent compounds are also categorized into two sections: polar covalent and nonpolar covalent. Furthermore, polar covalent compounds dissolve in water, while nonpolar covalent compounds do not.
The lab manual states that for the titration of NaOH and HCl, a volume of 7mL of titrant should complete the reaction, however, the average for the experiment was only 6.25mL. This smaller amount of NaOH could have occurred by adding too much phenolphthalein, which would have caused the substance to turn pink sooner, rather than when the reaction was complete since phenolphthalein is a weak acid. Another example of error occurred in the titration of NaOH and H2SO4, a substantial difference appeared in the theoretical ratio of 2:1 and the experimental ratio of 2.5:1. This could have occurred by adding past the titration end point, resulting in more NaOH than necessary, thus altering the ratio. Both reactions involving Ba(OH)2, had relatively low percent errors, especially in the HCl reaction (approximately 5%) and a higher percent error with H2SO4 (approximately 20%).
The mass of vinegar used during the experiment was 4.108 grams. It was determined that there were .003129 moles of CH3COOH in the vinegar sample. Using this information and the molar mass of CH3COOH, which was 60.05 g/mol, the mass of acetic acid in the vinegar was calculated: 4.Vinegar is a 5% aqueous solution of acetic acid. Since the mass of acetic acid within the vinegar was calculated as .18789 g in step 3, the percent of CH3COOH was calculated using the following equation: To calculate the percent error, the experimental value of 4.5% acetic acid in vinegar was subtracted by the theoretical value of 5% and divided by 5% to yield a percent error of 8.54%. The following is a copy of the calculations done using decimals: 5.The equivalence point of the titration curve measured in step 1 was 25.25 mL of NaOH.
CLAIRE MUNTING 29/01/2018 Criterion C EFFECTS OF SURFACE AREA OF CALCIUM CARBONATE UPON RATE OF REACTION Calcium Carbonate Chips 1 Introduction: Within the current investigation, the effects of the surface area of Calcium Carbonate (CaCO3) in combination with Hydrochloric acid (HCl) upon its rate of reaction. CaCO3, commonly referred to as limestone, is an organic substance and is, in a sense, the crystallised “carbonic salt” of the element, calcium2. In addition to being a salt, the pH level of Calcium Carbonate is 9.91, and it is therefore, a basic substance, due to the fact that it is comprised of a pH level higher than 7, which is neutral3. HCl, however, is the bodily acid found in the stomach of human beings.
Synopsis This experiment is the determination of Calcium Carbonate (CaCO3) content in toothpaste with the use of back titration while demonstrating quantitative transfer of solids and liquids. A accurately weighed quantity of toothpaste was dissolved in excess volumes of HCl. This solution is then titrated with NaOH to find the volume of the excess HCl. The volume of HCl reacted, which is found by substracting the volume of given HCl with the volume of excess HCl reacted, can be further manipulated with mole fractions to find the mass of CaCO3 and thus the CaCO3 content in toothpastes.