Brown Invitational — Forensics

Forensics · Division C · Brown Invitational · 2024

107 questions · 142 points · 50 min· 27 questions from the original omitted

Passage

Life in plastic isn’t always fantastic. Barbie invited her closest friends and Ken to her Dreamhouse to commemorate her birthday. She was busy dancing the night away when someone stole Barbie’s ethically sourced squirrel fur coat!! Handprints were found made of powder 2 at the scene of the crime. Barbie used her expertise as a lawyer and police officer to investigate the party invitees. She collected their statements below:

Ken: Earlier that day Ken was relaxing in Barbie’s epsom salt spa contemplating the patriarchy. He arrived at the party in a spiffy silk pantsuit to impress Barbie, though she hardly noticed. He’s made of polyvinyl chloride.

Stacie: Stacie spent most of her day at the ranch. She rode to the party on her pet pony in a glittery spandex pantsuit. She’s made of polystyrene.

Racquelle: Raquelle was inspired by Cake Boss to bake Barbie a cake for her birthday using two powders. She was running late and wore her polyester cooking apron to the party. She’s made of HDPE.

Midge: Midge wore a cotton smock while creating a wildly inaccurate marble sculpture of Barbie’s face. She topped it off with a wig made of real human hair. She’s made of polypropene.

Allan: Allan spent most of the day stocking up the snack station for the party. Allan’s fingers and wool coat were covered in salty chip crumbs when he was fingerprinted at the station. Allan is made of PETE.

Dolls are getting so advanced these days! They even have fingerprints, which were conveniently taken for you to crack the case at the Barbie investigator station. The results were as follows:

Suspect	Fingerprint Type
Ken	Plain Whorl
Stacie	Double Loop
Raquelle	Tented Arch
Midge	Radial Loop
Allan	Central Pocket Loop

Powders Directions

PassageFor questions 10–25, 27–30

Identify the powders according to the number on the bag and answer the multiple choice questions below:

Question 10

1 pt

Which of the following is a correct and balanced chemical reaction between calcium carbonate and hydrochloric acid?

A. CaCO₃(aq) + HCl(aq) → CaCl(aq) + HCO₃(aq)B. CaCO₃(aq) + 2HCl(aq) → CaCl₂(aq) + H₂O(l) + CO₂(g)C. Ca(CO₃)₂(aq) + 2HCl(aq) → CaCl₂(aq) + H₂O(l) + 2CO₂(aq)D. CaCO₃(aq) + HCl(aq) → CaCl₂(aq) + HCO₃(aq)

Question 11

1 pt

Hydrochloric acid can help determine if a sample contains:

A. Sodium carbonateB. Sodium chlorideC. Magnesium sulfateD. More than one of the above

Question 12

1 pt

Which of the following reagents can be used to test for pH?

A. Benedict’s reagentB. PhenolphthaleinC. NaOHD. Iodine

Question 13

1 pt

Which of the following reagents will result in precipitation when reacted with calcium nitrate?

A. Benedict’s reagentB. Distilled waterC. NaOHD. HCl

Question 14

1 pt

If you dissolve cornstarch in Lugol’s iodine, what color does it turn?

A. Black/blueB. BrownC. ClearD. Purple

Question 15

1 pt

A solution turns yellow when it reacts with Benedict’s solution. What does this solution likely contain?

A. 0.5% glucoseB. 1% glucoseC. 0.5% sucroseD. 1% sucrose

Question 16

1 pt

Which ion is responsible for the reddish color of the result of the reaction between Benedict’s solution and a reducing sugar?

A. Cu⁺B. Cu²⁺C. Li⁺D. Fe²⁺

Question 17

1 pt

Which of the following is NOT a compound that is used to prepare Benedict’s reagent?

A. Anhydrous sodium carbonateB. Sodium citrateC. Copper sulfate pentahydrateD. Tetraamine copper sulfate

Question 18

1 pt

Benedict’s solution reacts with

A. GlucoseB. SucroseC. Ammonium chlorideD. More than one of the choices above

Question 19

1 pt

If you were to conduct a flame test on boric acid, what color would the flame be?

Question 20

1 pt

If you were to conduct a flame test on lithium chloride, what color would the flame be?

Question 21

1 pt

If you were to conduct a flame test on potassium chloride, what color would the flame be?

Question 22

1 pt

If you were to conduct a flame test on sodium, what color would the flame be?

Question 23

1 pt

What additional property does ammonium chloride have in a flame test?

A. MeltB. Release white smokeC. BothD. None of the above

Question 24

1 pt

Which of the following powders has a pH < 7?

A. Ammonium chlorideB. Potassium chlorideC. Sodium acetateD. Sodium carbonate

Question 25

1 pt

Which of the following powders is the most basic when dissolved in water?

A. Calcium carbonateB. Sodium carbonateC. Calcium sulfateD. Sodium bicarbonate

Question 27

1 pt

Which group of powders are very soluble in water?

A. Sodium acetate, potassium chloride, calcium sulfateB. Lithium chloride, calcium nitrate, magnesium sulfateC. Calcium nitrate, calcium carbonate, glucoseD. None of the above

Question 28

1 pt

What powder is used primarily as treatment for bipolar disorder and chronic neurodegenerative diseases?

A. Sodium carbonateB. Lithium chlorideC. Magnesium sulfateD. Potassium chloride

Question 29

1 pt

What powder can be used to control atrial fibrillation and seizures?

A. Magnesium sulfateB. Boric acidC. GlucoseD. Sucrose

Question 30

1 pt

What ion can easily contaminate other powders during a flame test?

A. CalciumB. PotassiumC. SodiumD. Lithium

Fibers Directions

PassageFor questions 3, 7–19

Identify the following fibers and answer the multiple questions below

Question 3

2 pts

When Fiber 3 is put under an electron microscope, this is what is seen:

What is Fiber 3?

A. NylonB. LinenC. SpandexD. Wool

Question 7

1 pt

Which of the following fibers is a seed fiber?

A. LinenB. NylonC. SilkD. Cotton

Question 8

1 pt

Which of the following fibers is a bast fiber?

A. CottonB. LinenC. NylonD. Silk

Question 9

1 pt

Which of the following fibers is NOT a synthetic fiber?

A. SilkB. PolyesterC. SpandexD. Nylon

Question 10

1 pt

Which of the following fibers is usually described as looking like flat ribbons under a microscope?

A. PolyesterB. SpandexC. CottonD. Silk

Question 11

1 pt

Which of the following fibers has different strands that appear in 3 different colors under a light microscope?

A. NylonB. LinenC. SpandexD. Polyester

Question 12

1 pt

Which of the following fibers will have a pungent odor (caused by sulfur) when burned?

A. NylonB. WoolC. SpandexD. Linen

Question 13

1 pt

Which of the following fibers may leave behind a cream-colored bead as residue when burned?

A. NylonB. WoolC. SilkD. Linen

Question 14

1 pt

Which of the following fibers melts when burned?

A. WoolB. NylonC. SilkD. Cotton

Question 15

1 pt

Which of the following fibers gives off the odor of burning paper when burned?

A. WoolB. PolyesterC. CottonD. Nylon

Question 16

1 pt

What was the first synthetic fiber?

A. PolyesterB. SilkC. NylonD. Spandex

Question 17

1 pt

Which of the following is a protein fiber

A. NylonB. SilkC. PolyesterD. Cotton

Question 18

1 pt

This fiber has scales protruding from the edge of the fiber causing it to tangle. What is this fiber called?

A. SilkB. CottonC. WoolD. Linen

Question 19

1 pt

What fiber produces sparks but not smoke when burned?

A. WoolB. LinenC. NylonD. Cotton

Hair Directions

PassageFor questions 1, 3–20

Identify the following hairs and answer the multiple choice questions below

The following hairs were collected from the suspects:

Question 1

2 pts

What kind of hair is in box A?

A. HumanB. CowC. SquirrelD. Horse

Question 3

2 pts

What kind of hair is in box C?

A. SquirrelB. BatC. HumanD. Horse

Question 4

1 pt

What is another name for the catagen stage of hair growth?

A. Resting stageB. Transitional root stageC. Shedding stageD. Actively growing root stage

Question 5

1 pt

How long does the catagen phase last?

A. One to two daysB. One to two weeksC. One to two monthsD. One to two years

Question 6

1 pt

What is another name for the telogen stage of hair growth?

A. Actively growing root stageB. Transitional root stageC. Resting stageD. Shedding stage

Question 7

1 pt

What percent of hair follicles are in the telogen stage of hair growth?

A. 15%B. 30%C. 45%D. 60%

Question 8

1 pt

What is another name for the anagen stage of hair growth?

A. Actively growing root stageB. Resting stageC. Transitional root stageD. Shedding stage

Question 9

1 pt

What percent of hair follicles are in the anagen stage of hair growth?

A. 20%B. 40%C. 60%D. 80%

Question 10

1 pt

Which gland works with the growth of hair?

A. Follicular glandB. Pineal glandC. Bulbourethral glandD. Sebaceous gland

Question 11

1 pt

Which portion of the hair can contain ovoid bodies?

A. CuticleB. CortexC. Medulla

Question 12

1 pt

What is the maximum medullary index for human hair

A. 1/4B. 1/3C. 1/2D. 2/3

Question 13

1 pt

Which of the following hairs usually has coronal scales?

A. BatB. CowC. SquirrelD. Horse

Question 14

1 pt

Which of the following hairs commonly has ovoid bodies?

A. BatB. CowC. SquirrelD. Horse

Question 15

1 pt

What is a major difference between human hair and animal hair?

A. Human hairs tend to have natural sheen, while animal hairs are always dull in appearanceB. Human hairs are generally consistent in color throughout the length of the hair shaft while animal hairs can exhibit radical color changes over a short distanceC. Human hairs lack a central medulla compared to animal hairsD. Human hairs exhibit a uniform texture while animal hairs vary significantly in texture along the length of the hair shaft

Question 16

1 pt

Which of the following hairs is around 10 micrometers wide, has an indistinct medulla, and a scale count of about 8 per 100 micrometers

A. SquirrelB. HorseC. BatD. Cow

Question 17

1 pt

Which of the following hairs is coarse, strong, usually has a hollow central canal, and fairly low in density

A. CowB. SquirrelC. HorseD. Human

Question 18

1 pt

What type of bonds are responsible for holding together the proteins in hair?

Question 19

1 pt

What is the protein that makes up your hair and your nails?

A. ElastinB. MelaninC. KeratinD. Folliculin

Question 20

1 pt

How many layers does hair have?

A. 1B. 2C. 3D. 4

Plastics

Question P1

2 pts

An unidentified plastic was found at the crime scene. It burns slowly with a yellow flame and has a waxy smell. What plastic is this?

A. PVCB. PSC. PPD. HPDE

Question P3

1 pt

Identify the correct plastic with the following monomer structure:

A. PVCB. LDPEC. PETED. PS

Question P4

1 pt

Rank the following plastics in order of increasing density: PVC, PS, HDPE, PETE

A. PVC < PS < HDPE < PETEB. PETE < PVC < PS < HDPEC. PS < HDPE < PVC < PETED. HDPE < PS < PETE < PVC

Question P5

1 pt

Which plastics polymerize by condensation?

A. PS and PPB. PC and PETEC. PETE and PSD. HDPE and LDPE

Question P6

1 pt

If a plastic floats in a saturated NaCl solution, sinks in a 10% NaCl solution, but floats in a 25% NaCl solution, what plastic could this be?

A. PETEB. PVCC. PMMAD. PC

Question P7

1 pt

True or False: Thermoplastic undergoes a curing process to become irreversibly hardened from a softer form.

A. TrueB. False

Question P8

1 pt

Are thermoset or thermoplastic plastics more conducive to recycling?

A. ThermosetB. ThermoplasticC. They are equally recyclableD. Neither is recyclable

Question P9

1 pt

What type of plastic would be used to make a garbage bag?

A. PolycarbonateB. Low-Density PolyethyleneC. PolypropyleneD. Polymethyl Methacrylate

Question P10

1 pt

What type of plastic is the most commonly used for making water bottles?

A. PETEB. HDPEC. PPD. PC

Question P11

1 pt

What is the density of polycarbonate

A. 1.7 g/cm³B. 1.5 g/cm³C. 1.9 g/cm³D. 1.2 g/cm³

Question P12

1 pt

What is the density of HDPE?

A. 0.51 g/cm³B. 0.63 g/cm³C. 0.95 g/cm³D. 1.02 g/cm³

Question P13

1 pt

What plastic has the characteristics of being less rigid, having high impact strength, lower temperature resistance, less resistant to chemicals, and lower ultimate tensile strength

A. PVCB. HDPEC. LDPED. PETE

Question P15

1 pt

What plastic has the characteristics of being translucent/waxy, weatherproof, easy to process, and low cost?

A. PVCB. HDPEC. LDPED. PETE

Question P16

1 pt

What plastic is easiest to recycle?

A. PETEB. HDPEC. LDPED. PVC

Question P17

1 pt

You find a floating plastic bag in a tree. What type of plastic is it primarily made of?

A. PETEB. PVCC. LDPED. PMMA

Question P19

1 pt

Barbie recently had to replace her car window. What plastic is it made of?

A. PMMAB. HDPEC. PVCD. Non-expanded PS

Question P20

1 pt

When Barbie goes biking, she always wears her safety helmet. What plastic is it made of?

A. PVCB. LDPEC. Non-expanded PSD. PC

Chromatography

PassageFor questions C4–C7

Perform paper chromatography on Pens 1 and 2, and then calculate the Rfs for each and answer the multiple choice questions below

Question C4

2 pts

What does Rf stand for?

A. Reabsorption factorB. Redistribution factorC. Relocation factorD. Retention factor

Question C5

2 pts

Why does doing paper chromatography on permanent marker ink result in an Rf of 0?

A. Permanent marker ink is polar, and paper chromatography uses water as its solvent which is also polarB. Permanent marker ink is nonpolar, and paper chromatography uses water as its solvent which is polarC. Permanent marker ink is polar, and paper chromatography uses water as its solvent which is nonpolarD. Permanent marker ink is nonpolar, and paper chromatography uses water as its solvent which is also nonpolar

Question C6

2 pts

What are the mobile and stationary phases of TLC?

A. Mobile: a nonpolar liquid or gas solvent; Stationary: silica gel or alumina coatingB. Mobile: silica gel or alumina coating; Stationary: a nonpolar liquid or gas solventC. Mobile: an organic solvent like water; Stationary: silica gel or alumina coatingD. Mobile: silica gel or alumina coating; Stationary: an organic solvent like water

Question C7

2 pts

What does HPLC stand for?

A. Heavy Polar Liquid ChromatographyB. High-Performance Lipid ChromatographyC. High-Performance Liquid ChromatographyD. Heavy Polar Lipid Chromatography

Spectroscopy

Question S1

3 pts

Identify the molecular ion peak:

A. 71B. 121C. 150D. 152

Question S2

3 pts

How many carbons are in the compound?

A. 1B. 2C. 4D. 5

Question S3

3 pts

How many Chlorine atoms are in the compound?

A. 0B. 1C. 2D. 3

Question S4

3 pts

How many Bromine atoms are present in the compound?

A. 1B. 2C. 3D. 4

Question S5

3 pts

Is there an even or odd number of nitrogen atoms?

A. EvenB. Odd

Question S6

5 pts

What is the structural formula of this compound?

A. C₅H₁₁BrB. C₅H₁₂BrC. C₄H₁₁ClD. C₃H₁₂N₂

Fingerprints

Question F1

3 pts

Identify the type of fingerprint in picture A:

A. Tented archB. Central pocket whorlC. Plain whorlD. Radial loop

Question F2

3 pts

Identify the type of fingerprint in picture B:

A. Radial loopB. Ulnar loopC. Central pocket loopD. Plain arch

Question F3

3 pts

Identify the type of fingerprint in picture C:

A. Plain whorlB. Central pocket loopC. Double loopD. Radial loop

Question F4

3 pts

Identify the type of fingerprint in picture D:

A. Tented archB. Ulnar loopC. Radial loopD. Central pocket whorl

Question F5

3 pts

Identify the type of fingerprint in picture E:

A. Central pocket loopB. Ulnar loopC. Accidental whorlD. Plain whorl

Question F6

3 pts

Identify the type of fingerprint in picture F:

A. Tented archB. Plain archC. Accidental whorlD. Double loop

Question F8

1 pt

Which of the following animals has fingerprints?

A. RabbitsB. BearC. CatD. Koala

Question F9

1 pt

What is the scientific name for a fingerprint?

A. Stratum basaleB. DermacyteC. DermatoglyphD. Hyperplasia

Question F10

1 pt

This type of fingerprint is made on soft surfaces and is moderately difficult to detect, but can be photographed without development:

A. VisibleB. LatentC. PatentD. Plastic

Question F11

1 pt

What is the purpose of dusting with common fingerprint development?

A. Provide good visibility and definition of fingerprint detailB. Works only on nonporous surfaces to provide permanent visualization of the printC. React with the eccrine component of the fingermark deposit to give a dark purple productD. To use violet vapors absorbed by the sweat deposition of the latent imprint and reveal the ridge pattern

Question F12

1 pt

What is the purpose of iodine fuming with common fingerprint development?

Question F13

1 pt

What is the purpose of ninhydrin with common fingerprint development?

Question F14

1 pt

What is the purpose of cyanoacrylate fuming with common fingerprint development?

Question F15

1 pt

When do unique fingerprints form after conception for humans?

A. 3 monthsB. 7 monthsC. 12 monthsD. 1 year

Tracks and Soil

Question T1

2 pts

Match the Tracks found at the crime scene to the cars of the suspects. A= Ken, B= Allan, C= Raquelle

A. AB. BC. C

Question T3

1 pt

What are the three main types of soil?

A. Loam, Clay, SiltB. Loam, Sand, ClayC. Clay, Silt, SandD. Loam, Sand, Silt

Question T4

1 pt

Which of the following has the finest grains?

A. ClayB. SandC. SiltD. Sandy Loam

Question T5

1 pt

If a soil is 30% Clay, 70% Sand, and 70% Silt, what is the identity of this soil?

A. Clay LoamB. Sandy ClayC. Silty ClayD. Sandy Clay Loam

Question T7

1 pt

Which of the following soils has the greatest diameter?

A. SiltB. SandC. Clay

Glass

Question G1

1 pt

Which arrow (top or bottom) is pointing to a radial fracture?

A. Top arrowB. Bottom arrow

Question G2

1 pt

Which arrow (top or bottom) is pointing to a concentric fracture?

A. Top arrowB. Bottom arrow

Question G3

1 pt

Which point of impact happened first?

Question G4

1 pt

Which point of impact happened second?

Question G5

1 pt

Which point of impact happened third?

Question G6

1 pt

Which point of impact happened fourth (aka last)?

Question G7

1 pt

What kind of glass is usually used in automobiles?

A. BorosilicateB. FlintC. CrownD. Tempered

Question G8

1 pt

What kind of glass is usually used in kitchenware?

A. BorosilicateB. FlintC. CrownD. Tempered