Lab Report Percent Yield

In this experiment, the precision of percent by mass of sodium carbonate was decent. It seemed to be consistent, although we seemed to have an outlier in our fifth trial. I believe this was due to human error of adding too much vinegar to this graduated cylinder. The accuracy of our results was decent in comparison to the rest of the class’s data, but our results were on the higher end compared to the averages of the class data, though not too high to be considered

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

The purpose of this lab was to determine the limiting reactant in a mixture of to soluble salts and the percent composition of each substance in a salt mixture.

Hypothesis/Prediction: The percent composition by mass of magnesium in magnesium oxide will not change significantly with each group that conducted the experiment. The composition of each substance should stay the same and any differences must be due to some error.

The goal of this experiment was to determine the empirical formula for a hydrate of magnesium sulfate and water. The technique that was used was measure the mass of the hydrate and then apply heat to evaporate the water. Then determine the mass of water that was in the hydrate and the mass of the remaining magnesium sulfate. The equation for the hydrate is determined by calculating the mole to mole ratio of the water and the anhydrous. The resulting formula will be formated as: MgSO4*_H2O

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

The purpose of this lab was to test the law of definite proportions for the synthesis reaction of combusting magnesium. In this lab, the polished magnesium ribbon was placed in covered crucible and was heated in order for it to react with Oxygen presented in air and in water provided. The result showed that Magnesium oxide formed through chemical reaction was made up of 60.19% magnesium and 39.81% oxygen, which is approximate proportion of both particles in every Magnesium oxide compound. From this lab it can be concluded that the law of definite proportion stating that the elements in a pure compound combine in definite proportion to each other is factual.

The purpose of this experiment is to verify the formula of magnesium oxide based on the masses of magnesium and the product (MgO). We verify the formula firstly by calculating the empirical formula of magnesium oxide and then calculating creating the magnesium oxide itself- a magnesium ribbon is combined with oxygen in the presence of air through combustion and this forms MgO. The empirical formula of a compound is the simplest method of expressing a chemical formula in whole-number ratios of the constituent atoms that are consistent with masses measured in the experiment; whereas the molecular formula expresses the chemical formula using the actual number of atoms. For example, the molecular formula of anthracene is C14H10 while the empirical formula is C7H5.

The percent error of the lab of my partner and I can be attributed to the small amounts of air that made it into the graduated cylinder and the confusion we had with massing the lighter. If I were to do the lab again I would submerge the cylinder more carefully and read the directions more

It is not uncommon to have a percent yield less than 100% as was observed in our experiment. Imperfect percent yield can be interpreted that the condition were not optimal and could be improved. Despite careful measurements some component will still be lost during transferring between containers. One way to get a better percent yield is by minimizing transfers. A low percent yield could be a result of evaporation

Barajas 5th period chemistry class would demonstrate growth in the topic of percent composition of a compound or sample. This expectation was met by 20 (77%) out of the 26 students. The post-assessment is has 8 sections, but only five measure the ability to calculate the percent composition by mass of samples or compounds. The file “Criterion_6_Sample_1,” in the evidence tab, shows that Lily received a score of 100% on her post-assessment—which included five parts (points) that assessed the application of percent composition computations. Juan got an 87.5% score; however, both students correctly answer the 5 sections pertinent to the goals being measured. Both correctly determined that Magnesium Hydroxide is composed of 41%, 55%, and 3% magnesium, oxygen, and hydrogen respectively. Their work demonstrates the accurate use of formula masses and the application of percent composition equations. Just like them, 15 other students demonstrated equal ability to calculate the same percentages. The rating for this goal is high for the 17 students who got perfect scores, average for the 3 students who demonstrated 40 to 60 % growth, low for the 2 students who got zeros in the post-assessment, and uncertain for those students who had recurring absences and failed to participate in the growth goals set for

After conducting experimentations to find the best fit ratio that will produce the most amount of magnesium carbonate and highest percent yield, having a procedure was very helpful. The procedure used was very effective in helping the group collect and record precise results. The procedure was effective in the way that it was easy to follow with short, straightforward- to the point steps. In addition, the procedure included all the masses of the substances needed to collect for each trial, as well as the other materials that needed to be weighed. However, even with a competent procedure, one can’t predict what will go well and what will go wrong. An example of something that went well would be having all the materials that was needed before

) Suppose that some magnesium oxide smoke had escaped during the investigation, the Mg:O ratio would have increased from 58% to 72%. The final mass of MgO would have decreased because the magnesium oxide smoke is part of the product and when some of it escapes, it decreases the final mass.

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?

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.