Types of poisonous gases, their effect on the body. Characteristics of explosive and noxious gases most commonly found in reservoirs and underground facilities Colorless, odorless gas
Ethylene (ethene) is a colorless gas with a very faint sweet smell, slightly lighter than air, and slightly soluble in water.
C 2 - C 4 (gases)
C 5 - C 17 (liquids)
From 18 - (hard)
Alkenes are insoluble in water, soluble in organic solvents (gasoline, benzene, etc.)
lighter than water
With increasing Mr, the melting and boiling points increase
The simplest alkene is ethylene - C 2 H 4
Structural and electronic formula ethylene look like:
In the ethylene molecule, one s- and two p-orbitals of C atoms ( sp 2 - hybridization).
Thus, each C atom has three hybrid orbitals and one non-hybrid orbital. p-orbitals. Two of the hybrid orbitals of C atoms mutually overlap and form between C atoms
σ - connection. The remaining four hybrid orbitals of C atoms overlap in the same plane with four s-orbitals of H atoms and also form four σ-bonds. Two non-hybrid p-orbitals of C atoms mutually overlap in a plane that is perpendicular to the plane σ - bond, i.e. one is formed P- connection.
By it's nature P- connection sharply differs from σ - connection; P- the bond is less strong due to the overlap of electron clouds outside the plane of the molecule. Under the influence of reagents P- the connection is easily broken.
The ethylene molecule is symmetrical; the nuclei of all atoms are located in the same plane and the bond angles are close to 120°; the distance between the centers of C atoms is 0.134 nm.
SP 2 - hybridization:
1) Flat trigonal structure
2) Angle - HCH - 120°
3) Length (-C=C-) bond - 0.134 nm
4) Bonds - σ, P
5) Impossible to rotate relative to (-C=C-) connection
If the atoms are connected double bond, then their rotation is impossible without electron clouds P- the connection is not opened.
Explosive and harmful gases are most often found in tanks and underground structures: methane, propane, butane, propylene, butylene, carbon monoxide, carbon dioxide, hydrogen sulfide and ammonia.
Methane CH 4(marsh gas) - colorless, odorless, combustible gas, lighter than air. Penetrates into underground structures from the soil. It is formed during the slow decomposition of vegetable matter without access to air: during the decay of fiber under water (in swamps, stagnant waters, ponds) or the decomposition of plant residues in coal deposits. Methane is integral part industrial gas and, in case of a faulty gas pipeline, can penetrate into underground structures. Not poisonous, but its presence reduces the amount of oxygen in air environment underground structures, which leads to disruption of normal breathing during work in these structures. When the content of methane in the air is 5-15% by volume, an explosive mixture is formed.
Propane C 3 H 8, butane C 4 H 10, propylene C 3 H 6 and butylene C 4 H 8- colorless combustible gases, heavier than air, odorless, difficult to mix with air. Inhalation of propane and butane in small amounts does not cause poisoning; propylene and butylene have a narcotic effect.
Liquefied gases with air can form explosive mixtures with the following content, % by volume:
Propane 2.1-9.5
Butane 1.6-8.5
Propylene 2.2-9.7
Butylene 1.7-9.0
Means of protection - hose gas masks PSh-1, PSh-2, self-rescuers SPI-20, PDU-3, etc.
Carbon monoxide CO- colorless gas, odorless, flammable and explosive, slightly lighter than air. Carbon monoxide is extremely poisonous. The physiological effect of carbon monoxide on a person depends on its concentration in the air and the duration of inhalation.
Inhalation of air containing carbon monoxide above the maximum permissible concentration can lead to poisoning and even death. When the content in the air is 12.5-75% by volume of carbon monoxide, an explosive mixture is formed.
Means of protection - a filtering gas mask of the SO brand, self-rescuers SPI-20, PDU-3, etc.
Carbon dioxide CO 2(carbon dioxide) - a colorless gas, odorless, with a sour taste, heavier than air. Penetrates into underground structures from the soil. Formed as a result of the decomposition of organic matter. It is also formed in reservoirs (tanks, bunkers, etc.) in the presence of sulfocoal or coal in them due to its slow oxidation.
Getting into the underground structure, carbon dioxide displaces air, filling the space of the underground structure from the bottom. Carbon dioxide is not poisonous, but it has a narcotic effect and can irritate mucous membranes. At high concentrations, it causes asphyxiation due to a decrease in the oxygen content in the air.
Means of protection - hose gas masks PSh-1, PSh-2, self-rescuers SPI-20, PDU-3, etc.
Hydrogen sulfide H 2 S- colorless flammable gas, has an odor rotten eggs, slightly heavier than air. Poisonous, affects nervous system irritates the respiratory tract and eyes.
Means of protection - filtering gas masks of grades V, KD, self-rescuers SPI-20, PDU-3, etc.
Ammonia NH3- a colorless combustible gas with a pungent characteristic odor, lighter than air, poisonous, irritating to the eyes and respiratory tract, causes suffocation. When the content of ammonia in the air is 15-20% by volume, an explosive mixture is formed.
Means of protection - a filtering gas mask of the KD brand, self-rescuers SPI-20, PDU-3, etc.
Hydrogen H 2 It is a colourless, odorless, flammable gas, much lighter than air. Hydrogen is a physiologically inert gas, but at high concentrations it causes asphyxiation due to a decrease in oxygen content. When acid-containing reagents come into contact with the metal walls of containers that do not have an anti-corrosion coating, hydrogen is formed. When the hydrogen content in the air is 4-75% by volume, an explosive mixture is formed.
Oxygen O 2- colorless gas, odorless and tasteless, heavier than air. It does not have toxic properties, but with prolonged inhalation of pure oxygen (at atmospheric pressure), death occurs due to the development of pleural pulmonary edema.
Oxygen is not combustible, but is the main gas supporting the combustion of substances. Highly active, connects with most elements. Oxygen forms explosive mixtures with combustible gases.
Natural gas is a mineral found in the Earth's interior in a gaseous state. It can represent either individual accumulations (gas deposits) or a gas cap of oil and gas fields. Natural gas and its components are widely used in the national economy.
Composition of natural gas
Natural gas is 98% methane CH4, the properties of which almost completely determine the properties and characteristics of natural gas. It also contains methane homologues - C3H8 propane, C2H6 ethane and C4H10 butane. Sometimes natural gas may contain hydrogen sulfide, helium and carbon dioxide.
Methane (CH4)- colorless and odorless gas, lighter than air. Methane is combustible, but rather easily stored. Most often used as a fuel in industry and everyday life.
Ethane (C2H6)- a colorless and odorless gas, slightly heavier than air. Flammable no less than methane, but not used as a fuel. It is mainly used to produce ethylene, which is the most demanded organic matter worldwide. It is the raw material for the production of polyethylene.
Propane (C3H8)- also a gas that is odorless and colorless, poisonous. Possesses useful property: at low pressure, propane liquefies, which greatly facilitates the process of separation from impurities and its transportation. Lighters are fueled with liquefied propane.
Butane (C4H10)- very similar in properties to propane, but has a higher density. Twice as heavy as air. Propane and butane are widely used today as an alternative fuel for cars.
Carbon Dioxide (CO2)- low-toxic colorless gas, odorless, but with a sour taste. Unlike other components of the natural gas composition (except helium), carbon dioxide is not flammable.
Helium (He)- an inert colorless gas, the second lightest (after hydrogen), odorless. Under normal conditions, it does not react with any of the substances. It is non-flammable and non-toxic, but can cause anesthesia at elevated pressure. The lightness and non-toxicity (unlike hydrogen) of helium have found their application. Helium fill airships, balloons and hot air balloons.
Hydrogen sulfide (H2S)– can sometimes be included in natural gas. It is a heavy colorless gas with a pungent odor of rotten eggs. Extremely poisonous, even a small concentration can cause paralysis of the olfactory nerve. Despite its toxicity, hydrogen sulfide is used in small doses for hydrogen sulfide baths, as it has good antiseptic properties.
Natural gas is the best type of fuel
Natural gas is important source energy, allowing to reduce pollution and contributing to the maintenance of a normal ecological situation. Compared to other energy sources, it has several advantages:
- burning, it emits only carbon dioxide and water vapor, this is a mixture that we usually breathe on the street;
- when burned, it does not emit soot and smoke;
- ignites quickly and its combustion process is easy to control;
- almost does not contain solid impurities and other harmful components;
- relative cheapness, due to an easier method of extraction and transportation.
In terms of its energy properties, natural gas is second only to oil, which releases more energy when burned. But unlike oil, which must first be processed, natural gas requires little or no pre-treatment.
Poison gas is toxic Chemical substance, which causes intoxication of the body and damage to internal organs and systems. It enters through the respiratory system, skin, gastrointestinal tract.
List of poison gases according to their toxicological effects:
- nerve agents - carbon monoxide, sarin.
- Skin-blisters - lewisite, mustard gas.
- Asphyxiants - phosgene, diphosgene, chlorine.
- Lacrimal - bromobenzyl cyanide, chloroacetophenone.
- General impact - hydrocyanic acid, cyanogen chloride.
- Irritant - adamsite, CR, CS.
- Psychotomimetic - BZ, LSD-25.
Consider the most dangerous gases, the mechanism of their defeat, signs of poisoning in humans.
Sarin
Sarin is a poisonous liquid substance that at a temperature of 20 °C quickly evaporates and has a nerve-paralytic effect on the human body. As a gas, it is colorless and odorless, most dangerous if inhaled.
Symptoms appear immediately upon inhalation. The first signs of poisoning are shortness of breath, constriction of the pupil.
Clinical manifestations:
- irritation of the nasal mucosa, liquid discharge;
- salivation, vomiting;
- chest tightness;
- shortness of breath, blue skin;
- spasm of the bronchi and increased formation of mucus in them;
- pulmonary edema;
- severe cramps and pain in the abdomen.
In case of ingestion of high concentrations of sarin vapours, severe brain damage occurs after 1-2 minutes. A person cannot control the physiological functions of the body - involuntary defecation and urination. There are convulsions, convulsions. A coma develops followed by cardiac arrest.
Mustard gas
Mustard gas is mustard gas. it chemical compound blistering action. In liquid form, the substance has the smell of mustard. It enters the body in two ways - by airborne droplets and by contact of liquid with the skin. Has a tendency to accumulate. Signs of poisoning appear after 2-8 hours.
Symptoms of gas intoxication by inhalation:
- damage to the mucous membrane of the eyes;
- lacrimation, photophobia, feeling of sand in the eyes;
- dryness and burning in the nose, then swelling of the nasopharynx with purulent discharge;
- laryngitis, tracheitis;
- bronchitis.
If liquid enters the eyes, it will cause blindness. In severe poisoning with mustard gas, pneumonia develops, death occurs on the 3-4th day from suffocation.
Symptoms of gas poisoning upon contact with the skin are redness followed by the formation of vesicles containing serous fluid, skin lesions, ulcers, necrosis. Gas destroys cell membranes, disrupts carbohydrate metabolism, partially destroys DNA and RNA.
Lewisite
Lewisite is the strongest toxic substance, the vapors of which are able to penetrate through a chemical protection suit and a gas mask. It is a brown liquid with a pungent odor. The gas is classified as a skin blister agent. Acts on the body instantly and has no latent period.
Symptoms of gas poisoning in case of damage to the skin develop within 5 minutes:
- pain and burning at the point of contact;
- inflammatory changes;
- painful redness;
- the formation of bubbles, they quickly open;
- the appearance of erosion, heal for several weeks;
- in severe cases, when large concentrations of lewisite are ingested, deep ulcers form.
Gas inhalation symptoms:
- damage to the mucous membrane of the nasopharynx, trachea, bronchi;
- nasal fluid;
- sneezing, coughing;
- headache;
- nausea, vomiting;
- loss of voice
- feeling of pressure in the chest, shortness of breath.
The mucous membrane of the eyes is highly sensitive to poisonous gas.. It becomes red, eyelids swell, lacrimation intensifies. The person experiences a burning sensation in the eyes. When liquid lewisite enters the gastrointestinal tract, the victim begins to profuse salivation and vomiting. Sharp pains in an abdominal cavity join. Internal organs are affected, blood pressure drops sharply.
hydrogen sulfide
Hydrogen sulfide is a colorless gas with a pungent odor of rotten eggs. In high concentrations, the substance is very toxic. Entering the body by inhalation, symptoms of general intoxication develop - headache, dizziness, weakness. Hydrogen sulfide is rapidly absorbed into the bloodstream and affects the central nervous system.
Signs of gas poisoning:
- metallic taste in mouth;
- paralysis of the nerve responsible for smell, so the victim immediately ceases to feel any smells;
- respiratory tract damage, pulmonary edema;
- severe convulsions;
- coma.
Carbon monoxide
Carbon monoxide is a colorless poisonous substance, lighter than air. Entering the body through the respiratory tract, it is rapidly absorbed into the blood and binds to hemoglobin. This blocks the transport of oxygen to all cells, oxygen starvation sets in, and cellular respiration stops.
Symptoms of carbon monoxide poisoning:
- dizziness and headache;
- rapid breathing and heartbeat, shortness of breath;
- noise in ears;
- impaired visual acuity, flickering in the eyes;
- skin redness;
- nausea, vomiting.
In severe poisoning, convulsions are observed. The symptoms preceding the coma are growing - a drop in blood pressure, severe weakness, loss of consciousness. In the absence of medical care, death occurs within 1 hour.
Phosgene
Phosgene is a colorless gas with an odor of rotten hay. The substance is dangerous if inhaled, the first signs of intoxication appear after 4-8 hours. At high concentrations, death occurs within 3 seconds. Gas, getting into the lungs, destroys them, causing instant swelling.
Symptoms at different stages of poisoning:
- Pulmonary edema begins to develop in the latent period, when the victim is unaware of poisoning. The first signals from the body are a sweet, sugary taste in the mouth, nausea. Sometimes there is vomiting. A person feels a sore throat, itching and burning in the nasopharynx. There is a cough reflex, breathing and pulse are disturbed.
- After a latent period, the victim's condition deteriorates sharply. There is a strong cough, the person begins to choke. Blue skin and lips.
- Stage of progressive deterioration - strong pressure in the chest, leading to suffocation, the respiratory rate increases by 70 per minute (normal 18). The lungs produce a lot of fluid and mucus due to the decomposition of the alveoli. The person coughs up bloody sputum. Breathing becomes impossible. 50% of the BCC (volume of circulating blood) goes to the lungs and increases them. The mass of one lung can be 2.5 kg (norm 500-600 g).
In severe cases, death in 10-15 minutes. In case of gas poisoning of moderate severity, death occurs in 2-3 days. Recovery can occur 2-3 weeks after poisoning, but this is rare due to infection.
Hydrocyanic acid
Hydrocyanic acid is a colorless, light and mobile liquid with a pronounced odor. It blocks the chain of oxygen movement through the tissues, causing tissue hypoxia. Gas affects the nervous system, disrupting the innervation of organs.
Symptoms of respiratory poisoning:
- dyspnea;
- at the beginning of the development of the clinical picture, frequent breathing;
- with severe intoxication - respiratory depression and its stop.
Signs from the heart:
- slowing down of heart beats;
- increase in blood pressure;
- vasospasm;
- as symptoms increase - pressure drop, increased heart rate, acute cardiovascular failure, cardiac arrest.
Poison gases are strong, fast-acting substances. Emergency resuscitation measures are needed to save a person. With a favorable outcome, the victim needs long-term rehabilitation treatment.
1. colorless gas, without smell. 2. Heavier than air, 3. Poisonous, 4. Highly soluble in water, 5. Poorly soluble in water, 6. Slightly lighter than air, 7. Shows acid properties. 8. Non-salt-forming oxide. 9. Combines with blood hemoglobin, 10. Obtained by the decomposition of carbonates. 11. When high pressure liquefies, "dry ice" is formed, 12. Used to produce soda, 13. Used as gas fuel, 14. Used in the production of fruit waters, 15. Used in organic synthesis. 1. Colorless gas, odorless. 2. Heavier than air, 3. Poisonous, 4. Highly soluble in water, 5. Poorly soluble in water, 6. Slightly lighter than air, 7. Shows acidic properties. 8. Non-salt-forming oxide. 9. Combines with blood hemoglobin, 10. Obtained by the decomposition of carbonates. 11. At high pressure, it liquefies, "dry ice" is formed, 12. Used to produce soda, 13. Used as gas fuel, 14. Used in the production of fruit waters, 15. Used in organic synthesis.
Carbonic acid H 2 CO 3 Mr (H 2 CO 3) = = 62 Carbonic acid H 2 CO 3 Mr (H 2 CO 3) = = 62
Since carbonic acid is dibasic, it forms two types of salts: carbonates and bicarbonates (Na 2 CO 3, NaHCO 3) Alkali metal and ammonium carbonates are highly soluble in water, alkaline earth metal carbonates and some others are practically insoluble in water. Aluminum, iron, chromium carbonates cannot exist in aqueous solutions, as they undergo complete hydrolysis. Almost all bicarbonates are soluble in water Since carbonic acid is dibasic, it forms two types of salts: carbonates and bicarbonates (Na 2 CO 3, NaHCO 3) Alkali metal and ammonium carbonates are highly soluble in water, carbonates of alkaline earth metals and some others are practically insoluble in water . Aluminum, iron, chromium carbonates cannot exist in aqueous solutions, as they undergo complete hydrolysis. Almost all hydrocarbons are soluble in water.
Na 2 CO 3 - Soda ash - is used to produce alkalis, in the manufacture of glass, in everyday life as a detergent. NaHCO 3 - baking or drinking soda - is used in the food industry, for charging fire extinguishers, in medicine for heartburn. (CuOH) 2 CO 3 - malachite - in pyrotechnics, for the manufacture of mineral paints, in nature in the form of the mineral malachite (carved stone) CaCO 3 - chalk, limestone, marble - for the manufacture of lime, marble as a finishing stone, in agriculture for liming soils. K 2 CO 3 - potash - for the manufacture of soap, refractory glass, in photography. Na 2 CO 3 *10H 2 O - crystalline sodium carbonate - consumed by the soap, glass, textile, paper, oil industries. Na 2 CO 3 - Soda ash - is used to produce alkalis, in the manufacture of glass, in everyday life as a detergent. NaHCO 3 - baking or drinking soda - is used in the food industry, for charging fire extinguishers, in medicine for heartburn. (CuOH) 2 CO 3 - malachite - in pyrotechnics, for the manufacture of mineral paints, in nature in the form of the mineral malachite (carved stone) CaCO 3 - chalk, limestone, marble - for the manufacture of lime, marble as a finishing stone, in agriculture for liming soils. K 2 CO 3 - potash - for the manufacture of soap, refractory glass, in photography. Na 2 CO 3 *10H 2 O - crystalline sodium carbonate - consumed by the soap, glass, textile, paper, oil industries.