When chemicals are combined under certain conditions, different types of explosions may occur. The main types of explosions include: 1. **Deflagration**: - **Characteristics**: The combustion wave propagates at a low speed, usually below the speed of sound. The reaction is mainly carried out through heat conduction and convection. - **Example**: Solid organic matter such as wood and coal burns in an oxygenated environment. 2. **Detonation**: - **Characteristics**: The deflagration wave propagates at supersonic speeds, accompanied by drastic pressure and temperature changes. The reaction is completed in a very short time. - **Example**: High-energy explosives such as TNT (trinitrotoluene) and nitroglycerin. 3. **Thermal Explosion**: - **Characteristics**: The heat generated by the reaction cannot be effectively dissipated, resulting in a sharp rise in temperature, which triggers an explosion. - **Example**: Some organic peroxides decompose and explode under high temperature conditions. 4. **Pressure Explosion**: - **Characteristics**: The pressure in the container increases rapidly and exceeds the strength of the container, causing the container to rupture and generate an explosion wave. - **Example**: The explosion of combustible gas formed by excessive hydrogen or methane mixed with air in a closed space. 5. **Mixed explosion**: - **Characteristics**: Involves a combination of multiple reaction mechanisms, such as a combination of combustion and detonation. - **Examples**: In some industrial accidents, chemicals mixed together to cause complex explosions. **Examples of explosions caused by common chemical reactions**: - **Mixture of hydrogen and oxygen**: In the right proportions, hydrogen and oxygen can form explosive gases that explode when exposed to an ignition source. - **Decomposition of nitroglycerin**: Nitroglycerin is a high-energy organic compound that can decompose and explode when subjected to vibration, heat or shock. - **Mixture of ammonium sulfate and fuel oil**: A mixture of high-concentration ammonium nitrate and fuel oil (such as fertilizer explosives) can explode when exposed to an ignition source. **Precautions**: Chemical explosions are extremely dangerous, and the chemicals involved may cause serious harm to personal safety and the environment. Do not handle or mix chemicals without professional training and permission. In case of chemical hazards, contact a professional emergency department immediately for handling.