Percent Yield Lab Report

1. Our percent yield for alcohol was 84.2% which is average. We rushed through our vacuum filtration and probably did not let the solid dry long enough and might have not transferred all of the solid to the vacuum filtration from the beaker.

Usually, the percent is a good amount less than 100 because of multiple factors including transfer between different lab tools and when an unfulfilled reaction takes place. In the case of this experiment, copper most likely was lost between transfers of the Copper (II) solution, although loss was attempted to be minimized. Also, after the reaction, the copper was filtered and some mass could have lost if the reaction was not fully carried out and all of the copper did not precipitate out of the solution. But, when the copper oxidized overnight on the heater, the reaction with oxygen added mass to the ending mass of copper. These areas of losing and gaining mass throughout the procedure equaled out in the end because the percent yield was very close to 100% as the actual yield was 0.7 grams of copper and the theoretical yield was 0.71 grams of copper. If the copper did not oxidize, it is believed that the percent yield would not have been as close to 100% as it was because the oxygen gave mass back that was lost along the way of the

The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in

Numerous factors can determine the percentage yield of a chemical reaction. Such as the nature of the reaction, the conditions in which the reaction is carried out and the nature of the reactants used in the reaction. In this investigation the percentage yield was to be determined using the following chemical reaction:

Possible reasoning for a lower yield could be loss of product during separation process, particularly leaving some product behind in Erlenmeyer flask. Another possible explanation could be the wash of product with not enough cold water, which increases the solubility of the product, thus lowering the yield. Also the product was lost during purification process, recrystallization. Solid could be dissolved below the boiling point of the solution, thus required more solvent, resulting in a lower

1. Suggest at least one chemical reason why your percent yield is less than 100%. (Incomplete reactions? Side reactions? Stability of reagents?)

Data Analysis: When weighing the mass of our product you get 2.13 grams. Also when you figure out the percent yield you get 93.4%.

From the calculations in the data analysis, the actual percent composition of magnesium is 65.3% ± 1.7%, the actual percent composition of oxygen is 34.7% ±2.5%. The purpose of this lab was achieved as the percent composition of the magnesium oxide was determined and was used to test the law of definite proportions. The hypothesis was mostly correct as the results demonstrated that the actual percent composition was only slightly greater/lesser than the hypothesized percent composition. However, the actual percent composition may have been affected by several limitations during this investigation.

The purpose of Step 8 is to make sure we get the exact mass of the solution. There could be trapped molecules of water in the solution. Heating the solution would evaporate the water molecules.

Beakers 5-8 were set aside for later use. I then recorded by observation of beaker 1 in Table 1 on the Lab Reporting Form; this included smell, color, etc. 10 mL of vegetable oil was added to beaker 2, 10 mL of vinegar to beaker 3, and 10 mL of liquid laundry detergent to beaker 4. Each beaker was mixed thoroughly with a wooden stir stick. My observations such as color and smell were annotated in Table 1 on the Lab Reporting Form. Next, I cut the cheesecloth into five different pieces. I took one piece of cheesecloth and folded it so it was 4 layers thick. I then placed it into the funnel. 60 mL of soil was measured out using the 100 mL beaker and placed into the cheesecloth lined funnel. The funnel was then put inside beaker 5. The contents of beaker 1 (water) were poured through the funnel and let filter for 1 minute into beaker 5. My observations were recorded on Table 1 on the Lab Reporting Form. I repeated the process of creating a filter of cheesecloth and soil and filtered the contents of beaker 2 (vegetable oil) into beaker 6, beaker 3 (vinegar) to beaker 7, and beaker 4 (detergent) to beaker 8. All observations were recorded on Table 1.

2. (5 pts) List and explain the names and affiliations of the various characters/stakeholders in this story – I’m looking for us to use the story to map out the complexities that are generally associated with solving public health puzzles – the stakeholders you list and explain here should apply to many of the cases we consider going forward.

Reaction with Magnesium sulfate: Few drops of Magnesium sulphate were added to the test tube. White precipitates were formed. 3. Reaction with HCl: Few drops of 06 molar HCl were added to the test tube. Reaction did not occur at low concentration of HCl.

The percentage of the product being recovered is more than 50% which is 59%. The Percentage yield obtained is not 100% as what we expected, this might be due to the spillage of the benzoic acids when it was being measured or transferred and the benzoic acid was not weighed properly. It might also be caused by the errors when the benzoic acids solution was not filtered properly and they might have trapped in the filter paper.

In Chemistry, when a student conducts their experiment and is asked to calculate the percent yield for their reaction it may be possible that they can get either a low percentage yield or a high one even above 100%. The first thing they need to understand what a percent yield is to begin with. A percent yield is calculated to be the experimental yield divided by theoretical yield multiplied by 100, basically it is the total amount of product that could be created in a reaction, calculated referring to the beginning amount of the limiting reagent. The question here is if this is the result of a violation of the law of conservation of matter?

From 0.0M to 0.3M the percentage change in mass decreases which is to be expected as the water potential of the solution is becoming more negative, which means that less water will transfer from the cells into solution. At 0.3M to 0.4M there is a slight anomaly as the change in mass goes down by only 1%, which can easily be seen as the gradient of the line alters dramatically. However between 0.4M and 0.5M the gradient returns to that observed between 0.0M and 0.3M, the change in percentage change also returns to normal. This anomaly is most likely due to an error made when weighing the sample either before or after being put into the solution. It could also have happened because the sucrose solution may have been contaminated, or prepared inaccurately, e.g. if the molarity had been closer to 0.2M then the percentage change in mass would have been greater, that would explain the result found.