Percent Yield Lab Report PDF

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Percent Yield Lab Report Instructions: For this investigative phenomenon, you will need to determine the percent yield of magnesium oxide from the given reaction to determine if it is a useful commercial process. Record your data and calculations in the lab report below. You will submit your completed report.

Title: percent yield lab

Objective(s): I will react magnesium metal w the oxygen in the air by burning metal and determine the percent yield of magnesium oxide

Hypothesis: No hypothesis needed for this lab. Your theoretical yield calculation serves as your prediction for what you expect the lab to produce, and that will be determined later in the lab.

Procedure: Access the virtual lab. Because this lab is virtual, summarize the steps used to collect your data. In addition, list and explain your controlled variables, independent variable, and dependent variable for this lab. Materials: Percent Yield Virtual Lab Variables: Remember, controlled variables are factors that remain the same throughout the experiment. An independent (test) variable changes so that the experimenter can see the effect on other variables. The dependent (outcome) variable will change in response to the test variable. Controlled variables: bunsen burner Independent Variable: amount of magnesium

Dependent Variable:the yield Summary of Steps:

Data: Type the data in the data table below. Don’t forget to record measurements with the correct number of significant figures. Hint: Using the same instrument, you should have the same number of digits to the right of the decimal.

Data

Trial 1 Trial 2

Mass of empty crucible with lid

26.685

26.688

Mass of Mg metal, crucible, and lid

26.938

26.995

Mass of MgO, crucible, and lid

27.099

27.190

Calculations: Show your calculations for each of the following. Remember, calculations should follow rules for significant figures. 1. Write the balanced chemical equation for the reaction you are performing.

2Mg(s)+O2(g)=2MgO(s) 2. Subtract the mass of the crucible and lid (row 1 in the chart) from the total

mass of Mg, crucible, and lid (row 2 in the chart) to find the mass of magnesium for each trial. · Trial 1: .253 · Trial 2: .327 3. Subtract the mass of the crucible and lid (row 1 in the chart) from the total

mass of MgO, crucible, and lid (row 3 in the chart) to find the mass of magnesium oxide for each trial. This is the actual yield of magnesium oxide for each trial. · Trial 1: .414

· Trial 2: .502 4. Magnesium is the limiting reactant in this experiment. Calculate the

theoretical yield of MgO for each trial. · Trial 1: .6 · Trial 2: .589 5. Determine the percent yield of MgO for your experiment for each trial.

· Trial 1: 24.8% · Trial 2: 29.6% 6. Determine the average percent yield of MgO for the two trials.

27.2 Conclusion: Write a conclusion statement that addresses the following questions:  



Explain why the product had a higher mass than the reactant, and how this relates to conservation of matter. What sources of error may have contributed to the percent yield not being 100 percent? (Think about things that may have led to inaccurate measurements or where mass of the product could have been lost if this experiment was conducted in a physical laboratory.) How do you think the investigation can be explored further? During this lab I was performing an oxidation reaction because the whole objective of the lab is to create MgO through oxidation. You get a higher mass than the reactant because Mg is bonding with O to create the new substance MgO, which gains an atom, this relates to the conservation of matter because that states matter can not be destroyed or created from nothing but it can be converted from form to form. You could have had areas of error from inaccurate cuttings, or just not remeasuring the weights and lengths to assure the correct data. You could explore more through this la by using larger quantities, try exposing it to different types of air.

Post-Lab Reflection Questions Answer the reflection questions using what you have learned from the lesson and your experimental data. It will be helpful to refer to your chemistry journal notes. Answer questions in complete sentences.

1. When conducting this experiment, some procedures call for heating the substance

several times and recording the mass after each heating, continuing until the mass values are constant. Explain the purpose of this process and how it might reduce errors. By taking your time to record data you have a greater chance of more accurate and precise data outcomes which should help you to create a better percent yield because you will knowthe faults and strong points of the lab.

2. Your company currently uses a process with a similar cost of materials that has an

average percent yield of 91 percent. If the average percent yield of this process is higher than that, this could save the company money. What is your recommendation to the company? Please support your recommendation using your data, calculations, and understanding of stoichiometry gathered from this lab. I would run several varrying experiments to thry and raise percent yield because that would leave the company with a better outcome rate to present to the public. 91% is a high percent yield and having 100% is impossible but it is still viable to try and increase percent yield through experiments. They could try runnign these experiments with different measurements, heating time, cooling time, and overall temperatures....