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Separation of Mixtures
Separation of Mixtures
Learning Objectives:
Learning Objectives:
Upon completion of this experiment, students will have experienced:
(CLO1). Explain basic chemical concepts related to chemical changes, energy, and properties of matter.
(CLO2). Apply the methods of scientific inquiry
(CLO3). Analyze evidence to decide if generalizations or conclusions based on the obtained data are warranted
(MLO1-4) Explain the key components of the scientific method and differentiate between observations, inferences, and conclusions.
(MLO1-5) Differentiate between states (phases) of matter, pure substance or mixture, atoms and molecules. Explain whether a mixture is heterogeneous or homogeneous.
(MLO1-6) Categorize properties of matter as being quantitative or qualitative, physical or chemical, extensive or intensive.
Perform separations of mixtures using physical properties.
Experiment 1 studies how to use physical and chemical properties to separate different substances in a mixture. The laboratory assignment includes work that must be completed before the laboratory session and assignments that are completed after the laboratory session.
The assignments that must be completed are the following:
The assignments that must be completed are the following:
the pre laboratory writing assignment. This assignment must be submitted before the lab session. This assignment will NOT be accepted late.
Complete the Pre laboratory problems should be attempted BEFORE the laboratory session.
Complete the Laboratory Report of the experiment using the resources listed below and the data collected in the laboratory session
Complete the Post laboratory problems and Conclusion paragraph using the RERUNS method
Experiment 1This is the presentation for this laboratory assignment
Discussion
Discussion
In this experiment, we will discern the difference between observations and explanations. Scientists use several terms generally in describing the information received from a laboratory assignment: data, results, observations, inferences and conclusions. What do each of these terms mean? The Scientific Method is a process used by every scientist. What are the important parts of the method? Observation is an integral step in this method. These are characteristics directly observed with your senses; they may result in questions as to the reasons why we observe what has happened. Next with the use of one’s imagination, explanations (or hypotheses) can be suggested. These explanations can be tested through experimentation. If the experiments support an explanation, it can become a theory. Theories are always subject to further testing which can result in support, modification or discarding of the theory.
While performing these experiments, pay attention to any changes and record all observations including any questions you may have in the space provided in the laboratory manual. Be clear about it being an observation. Don’t confuse the observation with an inference or a conclusion. Conclusions are based on evidence collected from observations. They explain why something occurred or changed, the result or outcome. An inference is like a conclusion but is based on reasoning from the evidence. It explains what has happened or what we observed.
Pre Laboratory Writing Assignment
Pre Laboratory Writing Assignment
The student should complete two assignments before coming to the laboratory discussion. The first is a pre laboratory writing assignment that will be required for most of the laboratory assignments. The pre writing assignment may consist of up to three parts: a purpose statement of what the objectives of the assignment are, a theory paragraph containing background and an understanding of why we are completing this assignment and finally, a summary paragraph of the procedure explaining how the assignment will be completed.
The student should complete a pre laboratory writing assignment for Experiment 1 that contains a summary paragraph of the procedure explaining how the assignment will be completed and a list of the data that must be collected while performing this experiment.
A pre writing assignment is included in the example of a formal laboratory report at https://docs.google.com/document/d/1BGBPJS3VqNME4cKDrR50HqqrIYZt0sZ9UCg6IrS3MDk
This assignment will only be accepted before the laboratory session begins. No late assignments will be accepted.
Pre laboratory Problems
Pre laboratory Problems
The pre laboratory problems are questions about the laboratory assignment, background, definitions or procedure and calculations. These problems should be completed BEFORE coming to the class where the assignment will be discussed.
Go to the following website and watch the video about separating mixtures:
https://conceptualacademy.com/course/conceptual-chemistry/36-most-materials-are-mixtures
if the video does not open, click on the image circled and the video should open.
Answer the questions in the prelaboratory problems assignment on this video.
Chemistry References. These are some of the resources to find information about chemicals available online. Search for the physical properties of the chemicals listed in the pre laboratory problem which include sodium chloride, silicon dioxide, vanillin, naphthalene, zinc, copper and ammonium chloride.
Safety Data Sheets in an online search. The Safety Data Sheet also contains some limited information about the chemicals physical and chemical properties.
Appendix A: Physical properties of substances from the laboratory manual
ChemSpider: http://www.chemspider.com/
Wikipedia
The Merck Index is a reference book published by the Royal Society of Chemistry that contains articles and properties on almost every chemical that exists. This Index is available online at https://www.rsc.org/merck-index (subscriptions only)
The Handbook of Chemistry and Physics published by CRC Press contains tables and data about the elements, compounds but also basic values such as density and solubility of pure substance. This handbook is not available online without subscription.
PubChem is a free, searchable resource for accessible chemical information. This resource is available at https://pubchem.ncbi.nlm.nih.gov/
ChemSpider is also a free searchable resource for chemical information. This resource is available at http://www.chemspider.com/
Procedure and Report
Procedure and Report
Complete the individual parts of this laboratory using the resources given below and in the laboratory assignment.
Part A: Filtration and Separation of a mixture
Part A: Filtration and Separation of a mixture
A mixture of SiO2, CaCO3, and NaCl will be separated using the property of solubility. NaCl, table salt, is soluble in water, while SiO2, sand, and CaCO3, chalk, are not soluble in water. Calcium carbonate can be reacted with hydrochloric acid, HCl, creating a soluble calcium chloride compound. The NaCl and SiO2 will be collected using filtration, dried and weighed to determine the mass percent of each component of the mixture.
Exp1labReportmeasuringMassSalt.mp4This is a the beginning of the separation of sand, salt and chalk showing the measurement of the mixture, the dissolving of the salt, filtering and boiling of the salt solution to dryness.
All three components in the mixture will be separated first by dissolving the NaCl with water and then the first solution will be filtered.
Chemistry Lab Procedures from CSU Long Beach, episode 1, Gravity Filtration: http://youtu.be/jbVxg8SFY38
Guide to gravity filtration OFFICIAL: http://youtu.be/9aHtMYvWu3g
Filtration is the longest part of this experiment, but once the filtrate is collected, the water is boiled out of the salt water solution. This can also take a very long time. The quicker you begin the filtration and the subsequent boiling, the quicker you will complete this procedure.
Once the sand is separated, we will heat the sand in a drying oven to remove all of the water. How will we know when all the water is removed?
Part B: Separation of a solid mixture
Part B: Separation of a solid mixture
A mixture of vanillin and naphthalene will be separated using the difference in the solubility of each in different temperature solutions. Vanillin is very soluble in water at high temperatures, but not very soluble at low temperatures. Vacuum filtration will be used to separate the crystallized vanillin from the dissolved naphthalene in water.
Vacuum Filtration: http://youtu.be/IrD8IqflCkU
CSU Laboratory Procedures: Vacuum Filtration: https://youtu.be/e-4Hn5JGiow
Part C: Chemical and Physical Changes
Part C: Chemical and Physical Changes
Watch the videos or perform these activities with the directions provided in the laboratory assignment. Most of these assignments can be completed with common household materials.
Experiment 1: Antacid tablet
Experiment 2: Paper
Experiment 3: Baking soda and lemon juice
Experiment 4: milk and vinegar
Experiment 5: Kool-Aid and water
Experiment 6: Ice
Watch this video of dry ice. https://youtu.be/bNOol7Nh07Y
Experiment 7: Dropping out experiment
Just for fun: 10 Chemical Reactions that will Blow your mind. https://youtu.be/KNPoBoUt-HM
Post Laboratory Problems and Conclusion paragraph
Post Laboratory Problems and Conclusion paragraph
The post laboratory problems contains questions that determine your understanding of the laboratory assignment.
While the conclusion paragraph is a summary of what you learned in the assignment. The conclusion paragraph should not just be "this is what I learned" statement but a summary of the assignment, analysis of the data and results of the assignment and critical thinking about what was learned and why it is important. The RERUNS method described in Appendix D gives explanation and examples of the parts of the conclusion paragraph.
Experiment 1 Post Lab Problems and ConclusionReport abuse