Video of group observing the texture of white powders shows a group observing the grain size of the powders by using their hands lenses and by pinching a small amount in their fingers. The purpose of this lab is to learn to identify the properties of starch, sugar, baking soda, and salt. There are many types of reactions that occur in chemistry, and the one we are studying in this lab is a double displacement reaction. In this laboratory you will create a qualitative analysis scheme.
Biuret solution, iodine solution, litmus paper, vinegar. Extend 10 minutes identify a substance based on a chemical property 17. These three powders baking soda, baking powder and cornstarch are nearly impossible to identify by sight alone so we relied on chemical and physical property changes when the various substances were mixed with three liquids. Mystery white powder experiment forensic science using chemical change to identify an unknown substance phenomena occurrence or event students investigate. You are to use simple tests to find out what each powder is. Can chemical reactions be used to identify an unknown substance. Perform multiple experiments using several common powders such as corn starch, baking powder, baking soda, salt, and gelatin. Revisit the idea of identifying substances based on their chemical properties. After completing these qualitative tests, each group will receive an unknown corresponding to one of these white powders. The video of students testing water reaction with white powders shows students adding a few drops of water to each pile of powders and discussing their observations. When vinegar was added to the powders, powder a formed a pasty homogeneous mixture once more. A temporary lab facility has been prepared at the high school. Pdf physicochemical properties of egg white powder from. White powders a lab on standardized tests used to identify unknown substances objectives you will perform a series of tests to determine the physical and chemical characteristics of several unknown powders.
In order to determine if it is illegal or not the crime lab will identify the substance using chemistry. The unknown white powders are delivered to you in the lab so you can determine their identity. Baking soda, sugar, flour, cream of tartar, and chalk. How many of the white powders will be present in the unknown mixture you are trying to identify. Powder color texture ph iodine water vinegar heat solubility. You will then analyze a white powder collected from a locker at your high. The binary 2component mixtures will be subjected to a battery of similar qualitative tests, and the observed data. Compare the data with results you collected as you performed various test on the 6 white powders. To identify an unknown white powder from a list of five substances by observing physical and. By performing various tests, they are able to identify whether their powder is baking soda, baking powder, citric acid, corn starch, or detergent. Each of these powders can be superficially described as a dry white powder, but they have different chemical and physical properties.
You are then expected to run the sample through all of the testing that you performed on the 6 powders. Once you have completed the analysis of the 6 powders, you will be given a sample of the powder from the vial in the victims home. The white powders library consists of spectra of commonly found white powders. Remember a physical change involves a change in a physical property but the. Students will create a professional lab report, journal article, or. Vinegar, iodine solution, water, and radish or an indicator using a reaction cell plate or an index card, place a small amount of the solid powder into a reaction well, then add a few drops of the test reagents to each of the 5 powders. Cc0 public domain white powders found at known or potential crime. The unknown white powders are waiting for you in the lab.
Take one cup with white powder about 1 tablespoon and a stir stick. New laser technology can identify unknown white powders. You will need to develop your own procedure for this lab by reading the material given in this hand out. New laser technology can identify unknown white powders from safe distance 8 october 2018 credit. Later you will compare these results with those from the tests run on the unknown powders collected during the locker seizures. You will run tests on each of the white powders and record your results. White powders lab 2014 hamilton township high school. Students observe physical and chemical properties of white powders and then use those initial observations to help them. After completing these qualitative tests, each group will receive an unknown containing only two of these white powders. Fifth grade lesson using properties to identify white powders. White substance analysis and identification lab target audience 912 background and notes.
Use their observations to determine the composition of a mixture of 2 unknown white powders. You have learned how to describe matter based on its physical and chemical properties. Even though they have their suspicions, chemical and physical analyses must. The library includes 165 spectra of commercially available white powders e. White powders library listing 165 spectra this library is particularly useful to homeland security and national guard investigators. In previous labs, youve seen that many physical properties can be used to distinguish one material from another think about density and your first week of lab and even separate materials from one another think about properties like size, color, magnetism, and other. White powders a lab on standardized tests used to identify. The goal of this lab is to identify all five of the unknown white powders you are given. Physical changes can be tearing, grinding, melting, boiling, dissolving or any change that does not change the chemical identity of the.
The unknown mixture will contain two or three white powders or clear liquids that the students. Take on the role of a forensic chemist to identify unknown substances. Lab report 02 five white powders scientific observations. Instead, use the wafting technique shown by the teacher. A white powder is found spilled on the kitchen floor of a crime scene. Analysis of white powder lab by ashley obrey on prezi. You will perform a battery of test on various known samples to determine the chemical and physical properties of those substances. The results of the research on the known powders can then be used to analyze several unknowns using the scientific method. A similar powder is found on the shoes of a suspect in the crime. In this lab, you will play detective and use your chemistry knowledge to try to solve a crime. You will utilize your test results to identify an unknown substance.
Students will conduct a variety of chemical qualitative and quantitative analysis tests to gather data about a variety of known white powders and clear. In the exploration minilab today in class, our objective was to be able to distinguish three seemingly identical white powders. After weighing the precipitate, it is possible to come up with the limiting reagent, theoretical yield, and percent yield of this experiment. To identify an unknown white powder from a list of five substances by observing physical and chemical properties and changes in those properties. When equal masses of na 2 co 3 and cucl 2 are reacted, a solid precipitate of cuco 3 is formed. Mystery powders operating guide unit 7 crime scene chemistry u7. You will observe their chemical and physical properties to identify them. Analysis of a mystery powder as part of the investigation of a crime scene, detectives note that a white powder is found at the location. You have also learned some clues that tell you whether a physical change or a chemical change is occurring.
The unknowns can be a single powder or a combination of the known powders. To do this you must first carry out a series of tests on the white powders with known identities that are provided to. You will perform a series of tests to determine the physical and chemical characteristics of several unknown powders. A forensic scientist may discover powder at a crime scene. Identifying the mystery powders using chemical or physical properties. Complete the enlarged mystery powders lab paper to compile what each of the groups found. By this definition, flowability is sometimes thought of as a onedimensional characteristic of a powder, whereby powders can be ranked on a sliding scale from freeflowing to nonflowing. Prior knowledge questions do these before using the gizmo.
Powder b only slightly dissolved after some time had passed, and powder c fizzed once again, meaning that it reacted to the alkalinity of the water. Chemistry is the study of matter and the changes that occur to matter. Activity 4 identification of white powders chem words ionic compound. Prepare unknown powder mixtures before the second part of the experiment. Unknown powders cornell center for materials research. Colemans approval on prelab questions before beginning the lab. You have 10 numbered samples of unidentified white powders, listed below.
Qualitative and quantitative analysis of white powders and. In your own words, what is your goal in todays lab. As with the prelab table, write na in the box if the test was not performed. Make observations of the powders reaction with different solutions. Differentiating white powders exploration lab dest917. Although each white mystery powder looks like the other. Visitors will do a series of simple chemical tests with three white powders. The objective of this study was to compare the physicochemical properties of egg white powder from eggs of different types of bird local kampung chicken, local fighting chicken, local serama. As part of your report, construct a table as shown below. Be sure to include the unknown number given to you in the lab for each of the five white solids. The mystery powders in this activity have different physical properties, even though they are all white. A simple definition ofpowder flowability is the ability of a powder to flow. Background information jackson high school has a drug problem. Physical and chemical changes background information.