1. For the demo experiment, the balanced chemical equation is as follows: (NH4)2Cr2O7(s)=Cr2O3(s)+N2(g)+4H2O(g). After the lightning of Ammonium dichromate, Chromium (III) oxide was formed while the Nitrogen and Water escaped into the atmosphere in a gaseous phase. Ammonium dichromate((NH4)2Cr2O7) gave rise to Chromium (III) oxide (Cr2O3), Nitrogen Gas(N2) and water (H2O) In terms of microscopic level, the ratio between reactants and products is as follows. One mole of Ammonium dichromate will give rise to one mole of 1 mole of Chromium (III) oxide and 1 mole of Nitrogen gas and 4 moles of Water is gaseous phase. To convert these into formula units, 1 mole of any compound will equal 6.022X1023. So based on this, 1 mole of Ammonium dichromate is 6.022X1023 formula units. 1 mole of Chromium (III) oxide is 6.022X1023 …show more content…
Based on the stoichiometric, the theoretical yield, actual yield and percent yield can be determined. In order to calculate the percent yield, the value for theoretical yield is required. Percent yield is determined by diving the actual yield by theoretical yield and multiplying by 100. The theoretical. 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. To determine the theoretical yield, the reactants should be converted from grams to moles based on the coefficients in the chemical equation and the moles should be incorporated into the mass of the reactants. When calculated, this would give rise to the theoretical
An error that could have been present during the lab includes not letting the zinc react completely with the chloride ions by removing the penny too early from the solution. For instance, the percent error of this lab was 45.6%, which was determined by the subtraction of the theoretical percent of Cu 2.5% and the experimental percent of Cu 3.64% and dividing by the theoretical percent of Cu 2.5%. This experiment showed how reactants react with one another in a solution to drive a chemical reaction and the products that result from the
The percent yield was calculated to be 129.7%. This high percent yield resulted from the presence of
To test for the presence of the ammonia cation, a scoop of the unknown compound was mixed with NaOH to see if the resulting solution had a noticeable smell that would affirm the presence of ammonia. A moist piece of pH paper was then held near the solution to see if the ammonium would dissolve the water on the pH paper. The next cation test performed was the flame test. A gram of the unknown compound was held by a metal stick above the flame of a Bunsen burner to see what color flame the compound would produce. The chart in the lab manual on page 63 was used to determine what cation correlated with what flame color.
It is also the real amount. Theoretical yield is found through a mathematical equation. The amount produced is another way of identifying theoretical yield. The limiting reactant is the reactant that is completely used in the reaction.
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.
To determine the rate of reaction there are many method to be used for example, measuring the mass after the product has been added and measuring the difference in mass on the duration of a digital scale. Another method, which will be used in this experiment is using a gas syringe to measure the volume of the gas which has been produced. The cylinder inside, will be pushed out to show a quantitative presentation of the volume produced by the reaction. Hypothesis
Copper Cycle Lab Report Ameerah Alajmi Abstract: A specific amount of Copper will undergo several chemical reactions and then recovered as a solid copper. A and percent recovery will be calculated and sources of loss or gain will be determined. The percent recovery for this experiment was 20.46%.
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 percent recovery of the copper was calculated using the equation, percent recovery = (the mass of the copper recovered after all the chemical reactions/the initial mass of the copper) x 100. The amount of copper that was recovered was 0.32 grams and the initial mass of the copper was 0.46 grams. Using the equation, (0.32 grams/0.46 grams) x 100 equaled 69.56%. The amount of copper recovered was slightly over two-thirds of the initial amount.
(150.22g/mol)(3.5 x 10^-3 mol of nucleophile) = 0.525 g Actual yield = 0.441 g, Percent Yield = (0.441g/0.525g) x 100% = 84% 10. Percent recovery from recrystallization = (0.172g/0.441g) x 100% = 38% 11.
The final product weight for percent yield was only the solid E product, which missed one half of the final product produce. If both products were weight, the percent yield would have been larger that it was. Instead of 22.33%, it could have been 44.66%. To prove that both products were obtained, but only one of the two products was analyze, a TLC plate of the DCM layer, that contains both products, and of the final product, was obtain.
Verna Wang Hannah Palmer CHEM 101-069 Lab 11-19-16 Stoichiometry and Limiting Reagents Lab Report Purpose: We are using the reaction of sodium hydroxide and calcium chloride to illustrate stoichiometry by demonstrating proportions needed to cause a reaction to take place. Background: Just like a recipe would call for a specific amount of one ingredient to a specific amount of another, stoichiometry is the same exact method for calculating moles in a chemical reaction. Sometimes, we may not have enough of or too much of one ingredient , which would be defined as limiting and excess reagent, respectively.
After the reaction is finished, the percentage composition of each element in the product can be found and used to calculate the empirical formula, which is the lowest whole number ratio
Properties of Substances Express Lab 1)The purpose of this lab was to compare the physical properties of different types of solids and how the properties of solids are determined by their intermolecular forces and their intramolecular bonds. Then we were to classify each type of solid as either ionic, metallic, non-polar molecular, polar molecular, or network. Paraffin wax classified as a non-polar molecular, Silicon dioxide was classifies as a network, Sodium chloride was classified as ionic, Sucrose was classified as polar molecular and Tin was classified as metallic. (2)The intermolecular forces that are present in Paraffin wax are dispersion forces, because it is non-polar and carries a negative charge. Followed by Sucrose that has