SciOly Circuit Lab -, Study notes of Electronics

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Forensics KEY

Clements High School

Calling all stellar forensic teams! Trophies for the Clements 2019 Invitational have been stolen, with 50 minutes remaining until the awards ceremony! Upon investigation, it turns out that Hearty Hart, the science olympiad sponsor and trophy-watcher, was “sleeping on the job” after a long night of dealing with pre-invitational antics. As he woke, he discovered a barren room, devoid of all the glistening trophies which had once inhabited the room. We have gathered some suspect profiles for you to analyze and crack before the start of the awards ceremony:

1. Uptown Usanga: (previous science olympiad sponsor) Interview: “What? Trophies were stolen? You see, this is what happens as soon as you don’t have me, the best sponsor, watching over you all! This turn of events is too unfortunate… Well, I’ve been very sick with a horrible cold and cough, so I definitely do not have the energy to be dealing with your antics!” Possible Motives: Possibly wants shiny trophies to entertain her newborn child, perhaps some hidden vengeance towards the science olympiad team… Physicalities: ● African american ● Loves to go to the gym, gym attire is what she wears on a near daily basis ● Loves to consume energy drinks to fuel her workouts ● Has a mild case of athlete's foot, very insecure about this fact. ● B+ blood ● Loves to meal prep, has characteristic containers for her food 2. Big Bad Wolfe: (the school’s band director) Interview: “That’s quite unfortunate. It seems that now you’ll have more time to practice your instrument!” Possible Motives: long standing feud with the school’s science olympiad organization, wishes more people cared about the band program Physicalities: ● Caucasian

1. Fill in the information regarding the powders found at the crime scene. Powder Identify [5pts each] Chemical formula of the powder [1pt each] Name ONE character that this powder could implicate. (suspects, victim, all or none) [3 pts each] 1 Sodium Acetate NaC2H3O2 hart 2 Magnesium Sulfate MgSO4 wolfe 3 Potassium Chloride KCl none 4 Boric Acid H3BO3 usanga 5 Ammonium Chloride NH4Cl sameer 6 Sodium Carbonate Na2CO3 hart 7 Potassium Chloride KCl none 8 Calcium Sulfate CaSO4 hart 9 Glucose C6H12O6 usanga
2. Name two common uses for all prime numbered powders. [1pt for each use] 2-MgSO4 : Bath salts; flotation therapy: isolation tanks. Used for meditation, relaxation, alternative medicine; Beauty products; sooths sore muscles, splinter removal, laxatives, prevent seizures in pregnant women; agriculture, Electrolyte to prepare copper sulfate (copper anode). First aid for BaCl2 poisoning.. Magnesium-hungry: potatoes, roses, tomatoes, lemon trees, carrots, peppers. sunscreen, skin care, treating sprains and asthma attacks, tofu coagulant, cure skin problems, beer brewing 3-KCl: Chemical feedstock—manufacture of KOH, potassium metal. Medicine, lethal injections, substitute for table salt (weak, bitter, unsalty flavor); alternative to NaCl in household water softener units. Once used as fire extinguishing agent (Super-K dry chemical) until the use of potassium bicarbonate (Purple-K) & heat packs until use of oxidation of metals or crystallization of NaH2C3O2. Used in water as completion fluid in petroleum, natural gas operations. De-icing products safer for pets plants. Bottled water. CO2 laser production 5-NH4Cl: Nitrogen source in fertilizers (90% world production. Main crops-Asia’s rice, wheat). Flux in preparing metals to be tin coated, galvanized or soldered. Expectorant in cough medicine. Produces low temperatures in cooling baths. Buffer solutions when used in ammonia.

NH4Cl is precipitated in fossils, Covers up any coloration. Eliminates reflection on glass and similar specimens for photography. Gives large squid species neutral buoyancy in seawater. Yeast nutrient in breadmaking, spices up salty licorice, gives crispiness to food. Other: electrolyte in zinc-carbon batteries (dry cell), shampoo, cleaning products, glue that bonds plywood. medical treatments, textile printing, fertilizer, fireworks food additive, leather, explosives, safety matches, hair shampoo, glue that bonds plywood, cleaning products, deodorant, blood pH, fabric 7-KCl: Fertilizer. Chemical feedstock—manufacture of KOH, potassium metal. Medicine, lethal injections (3rd, final drug used) - stops heart, cause death by cardiac arrest), result in influx of potassium ions. Electrical impulses in cardiac muscle cells (which keep the heart running) are dependent the concentration of K+ and Na+ ion inside and outside the cell membranes. Influx of K+ ions disrupts this and causes the resting potential to lower below the threshold potential disabling the cardiac muscle tells to repolarize before next impulse cycle sodium-free substitute for table salt (weak, bitter, unsalty flavor); alternative to NaCl in household water softener units. Once used as fire extinguishing agent (Super-K dry chemical) until the use of potassium bicarbonate (Purple-K) & heat packs until use of oxidation of metals or crystallization of NaH2C3O2. Used in water as completion fluid in petroleum, natural gas operations. De-icing products safer for pets plants. Bottled water. CO2 laser production

1. Draw the chemical structure for sucrose. [5pts]
2. T/ F : All disaccharides are reducing sugars. [1pt]
3. What element is considered a contaminant in many components and colors a flame during flame tests, what color does it taint the flame with? [1pt] Sodium; yellow
4. Describe how and why we can observe flame colors in a flame test. [3 pts] When the atoms of a gas or vapor are excited, for instance by heating or by applying an electrical field, their electrons are able to move from their ground state to higher energy levels. As they return to their ground state, following clearly defined paths according to quantum probabilities, they emit photons of very specific energy. This energy corresponds to particular wavelengths of light, and so produces particular colors of light. Each element has a "fingerprint" in terms of its line emission spectrum 7. What is the formula for the precipitate formed by Epsom salts and sodium hydroxide? MgSO4 + 2NaOH → NaSO4 + Mg(OH)2 precipitate Polymers--- [____/49pts]

1. The plastic sample floats in water and rubbing alcohol, but not in oil. What is it? (2pts) LDPE
2. Give the SPI (resin code for PVC, PS, PETE, LDPE, HDPE, and PP and give an example of each use. (1pt per correct answer, 12 max) Fibers/Hairs --- [___/ Specimens 1,2,3,6 were found at the crime scene. Image Fiber/Hair (2pts each) If fiber, specify kind of fiber (vegetable, synthetic, animal); if hair write “N/A” (1pt each) 1 cotton vegetable

2 wool animal 3 Horse N/A 4 cotton vegetable 5 Human N/A 6 Human (mongoloid)

N/A

1. Describe why cotton develops its convolutions, and name the process that reduces these convolutions. [2pts for how, 1pt for process]

d. ___island___________

1. The following fingerprint was found at the crime scene. Who do you think this implicates? (2pts)
2. What component of a fingerprint does ninhydrin react with to develop a print? (1pt) a. Amino acids Entomology ---
3. What is ADH?(3pts) a. Accumulated degree hour
4. What is algor mortis?(2 pts) a. Body cooling
5. What are the stages of decomposition? (4pts) a. autolysis(self digestion) b. Putrefaction (process caused by bacteria found w/in the body)
6. Which insects are the first after 24 hrs to come in contact with the carrion? (2pts) circle one. a. Blowflies b. Beetles c. Moths d. Fleshflies

Blood ---

1. What kind of blood smear is this? (2pts) a. amphibian/reptilian
2. What is erythroblastosis fetalis?(2pts)

a. Condition when fetus is Rh+ and mother is Rh-, causing the mother’s immune system to attack the fetus. Prevent by giving the woman an injection that will suppress the immune reaction to baby.

1. What is luminol? Why is it used in investigations? (3pts) a. A white pale yellow, crystalline solid that is soluble in most polar organic solvents, but insoluble in water. Investigators use luminol to detect trace amounts of blood at crime scenes as it reacts with the iron in hemoglobin.
2. A blood spatter hits the ground, making a spatter that is 5.3cm long and 2.43 cm wide. Calculate the angle that it hit the ground. Show your work. (4pts) a.
3. What is blood’s universal donor? (1pt) a. O-
4. What is Luminol, and how is it used in forensic application? (3pts) a. Luminol is a white-to-pale-yellow crystalline solid that is soluble in most polar organic solvents, but insoluble in water. Forensic investigators use luminol to detect trace amounts of blood at crime scenes, as it reacts with the iron in hemoglobin. Chemical that exhibits chemiluminescence, with a blue glow, when mixed with an appropriate oxidizing agent.
5. How are blood types determined? (2pts) a. Blood types are determined by the presence or absence of certain antigens on the surface of red blood cells.
6. This is the blood that was found at the scene. From this, who do you think this sample was derived from? Hart DNA ---
7. When was DNA fingerprinting invented? By whom? (2pts per answer) a. Alec Jeffries, 1984
8. What is PCR? Name and briefly describe its steps. (4pts) a. Polymerase chain reaction, used to synthetically replicate DNA. b. Denaturing (94-96 C) melting the h bonds of dna template c. Annealing (~68C) annealing of primers, hybridization d. Elongation/synthesis (72C) synthesizes complementary strand 5’ to 3’
9. When was DNA fingerprinting commercialized?(2pts) a. 1987

Analysis--- Explain who you believe is the suspect, and why. Be sure to include information on why individuals are not the suspect as well. Hearty Hart is suspect:

• mongoloid hair -sodium acetate from salt and vinegar chips -sodium carbonate from mooncakes -cotton from jeans -calcium sulfate from chalkboard use -AB - blood found at scene -LDPE connected to swim noodles -matching plain whorl fingerprint -blood type matches that of scene (+8) Usanga is not suspect: -not negroid hair -spandex from gym attire not found at scene -boric acid found at scene, could be linked to athlete foot treatment -not B+ blood -PETE found at scene, could be linked to her meal prep containers -glucose found at scene, could have been for athelete supplement -blood type does not match that of scene (+7) Wolfe is not suspect: -not caucasian hair
• PS from her styrofoam coffe cups -wool found at scene, connected to sweater -MgSO4 found at scene, connected to her face masks and body bath salts -cotton found at scene, connected to jeans -blood type does not match that of scene Sameer is not suspect: -caucasian hair does not match -spandex was not found at scene -ammonium chloride found at scene, fertilizer for plants -sodium carbonate, souffle baking soda -blood type does not match that of scene