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Chemistry in the Police Force

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Alex Mic

on 21 January 2014

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Transcript of Chemistry in the Police Force

Surprisingly, the police do more than just crash parties, catch us speeding, or drifting around corners.Chemistry is found in everything police men and women use. From tear gas and smoke bombs in riots, breathalyzer tests for impaired driving, to lie-detector tests, the use of chemistry in the police force is endless. In these slides, we will go through chemistry in nonlethal weapons, drug identification, and in criminal investigation (polygraph test).
Chemistry in the Police Force
The chemical formula of tear gas is C10H5ClN2 and is scientifically known as Chlorobenzylidenemalononitrile. CS for short and is solid at room temperature. Tear gas temporarily causes the eyes and nose to start running and may cause vomiting if inhaled too much.The only way to treat it is by letting the crystals dissolve in oxygen (O2) or neutralizing it with sodium metabisulfite (Na2S2O5).
Unlike tear gas, smoke bombs do not cause any effect to the body and can be made at home. Police use smoke bombs as a camouflage or to indicate a signal.
The chemical equation for smoke bombs:
5C12H22O11 + 48KNO3 --> 24K2CO3 + 55H2O +24N2 + 36CO2
Colors can be added by using a oxidizer, mainly potassium chlorate (KClO3), a sugar, and a solute, such as sodium bicarbonate (NaHCO3) for heat control. The color will evaporate into smoke by burning.
There are many types of drugs, from cannabis, synthetic, tablets, powders, and liquids. When it comes to identify these drugs, most police officers have a drug identification kit. This kit comes with examples of how all drugs look like, and the color test. There are many different color tests to quickly identify drugs by what color they turn the solution. Here are two examples:
- Marquis Color (Formaldehyde and concentrated sulfuric acid): Heroin/morphine : Purple
:Amphetamines : orange-brown

- Duquenois-Levine (Vanillin, acetaldehyde, ethyl alcohol, chloroform): Marijuana : Purple
Breathalysers are used to detect the amount of alcohol on the breath. How they work is simple: Ethanol on the breath is oxidized to acetic acid by a electrical current. the chemical formula for this process is:
CH3CH2OH + O2 -> CH3COOH + H2O
Police use breathalysers to prevent drinking and driving.
Otherwise known as the "lie-detector test", the polygraph test detects if you are lying or telling the truth. It measures breathing rate, blood pressure, pulse, and perspiration, and sometimes nervous movement. Certain questions would be asked by the officer, and the reaction of the subject would be recorded and can determine whether they lied or not. Chemicals in the body trigger, leading to react noticeably to stressful situations.
Chemistry in Polygraph Tests
The police often use nonlethal weapons in out of control riots. The most common nonlethal weapons used are smoke bombs, tear gas, and pepper spray. If a riot breaks out, it is the responsibility of police officers to end it as quickly as possible before to much damage is done.
Chemistry in Nonlethal Weapons
This field in the police force is endless with a variety of large subjects. This field in the police force uses chemistry in the criminal brain to detect behavior changes, story change, and discovering useful information. Many chemical tests are used on the criminal to find the truth in the story of a crime and to prevent it from happening.
Chemistry In Drug Identification
Chemistry in the Criminal Investigation: Polygraph Tests
Chemistry in Polygraph Tests Continued
Chemistry in Drug Identifiers
Chemistry in Breathalyzers
Chemistry In Tear Gas
Chemistry in Smoke bombs
Chemistry in Pepper Spray
Also known as OC spray, pepper spray is a chemical compound which causes temporary blindness and pain to the eyes. Active ingredient is capsaicin (chilli plant) which extracted with ethanol (C2H6O), then evaporated. The chemical formula of pepper spray is: C18H27NO3
Treatment includes crying the wax out of your eyes or rising out with soap.
To identify drugs at a crime scene, police officers use many different kinds of tools to identify alcohol, cocaine, MDMA,heroine, etc. The police are trained and tested on their knowledge of how most drugs look like so they will know which tests will identify the unknown drug.
The possibilities and jobs are endless in the police force using chemistry. Criminals have a lot to worry about when it comes to the use of chemistry technology. The police have a lot on their hands, from stopping drug trafficking, controlling riots, and finding the truth of a crime. The use of chemistry in the police force is crucial to help solve a crime or to potentially save a life.
If you lie: The chemicals released is a chain reaction that starts in the brain. The brain signals the sympathetic nervous response which activates the stress gland which releases epinephrine (C9H13NO3) to flow into the blood stream which will cause the heart rate to increase and sweat glands to react. Releasing the main chemical that will cause your entire body to stress out; cortisol (C12H30O5). Which is how the polygraph test is able to detect a lie.
Chemistry in Polygraph Tests Continued
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