Video Experimental Relacionado
Updated: Jul 12, 2026

07:14
Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx
Published on: December 20, 2016
Reacciones de óxido de nitrógeno en el penacho urbano de Boston
Resumen
Los óxidos de nitrógeno se eliminan del aire urbano principalmente a través de la conversión química, con una vida atmosférica promedio de 5 a 6 horas. Este estudio cuantifica la tasa de eliminación en el penacho de Boston.
Área de la Ciencia:
- Química de la atmósfera química de la atmósfera.
- Ciencias ambientales Ciencias ambientales.
Sus antecedentes:
- Los óxidos de nitrógeno (NOx) son los principales contaminantes del aire que contribuyen al smog y a las lluvias ácidas.
- Comprender las tasas de eliminación de NOx es crucial para la gestión de la calidad del aire en entornos urbanos.
Objetivo del estudio:
- Para determinar la tasa de eliminación y conversión de óxidos de nitrógeno (NOx) en el penacho urbano de Boston.
- Para cuantificar el tiempo de vida atmosférico de NOx en condiciones urbanas específicas.
Principales métodos:
- Las mediciones aéreas se llevaron a cabo dentro de la pluma urbana de Boston.
- Las constantes de velocidad de pseudo-primer orden para la eliminación de NOx se calcularon en condiciones de luz diurna.
Principales resultados:
- La constante de velocidad media de pseudo-primer orden para la eliminación de NOx fue de 0,18 por hora (rango: 0,14 0,24 por hora).
- Las vías dominantes de eliminación identificadas fueron la conversión química en ácido nítrico y nitratos orgánicos.
- La tasa de eliminación calculada indica una vida atmosférica de NOx de aproximadamente 5 a 6 horas en el aire urbano.
Conclusiones:
- El NOx en las atmósferas urbanas tiene una vida atmosférica relativamente corta, alrededor de 5-6 horas.
- La conversión química en ácido nítrico y nitratos orgánicos es el mecanismo principal para la eliminación de NOx.
- Las mediciones aéreas proporcionan datos valiosos para comprender la dinámica de los contaminantes atmosféricos.
Videos de Conceptos Relacionados
Overview of Nitrogen Metabolism
Nitrogen is a very important element for life because it is a major constituent of proteins and nucleic acids. It is a macronutrient, and in nature, it is recycled from organic compounds and stored in the form of ammonia, ammonium ions, nitrate, nitrite, or nitrogen gas by many metabolic processes. Many of these metabolic processes are carried out only by prokaryotes.
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
Electrophilic Aromatic Substitution: Nitration of Benzene
The nitration of benzene is an example of an electrophilic aromatic substitution reaction. It involves the formation of a very powerful electrophile, the nitronium ion, which is linear in shape. The reaction occurs through the interaction of two strong acids, sulfuric and nitric acid.
2° Amines to N-Nitrosamines: Reaction with NaNO2
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
The Equilibrium Constant
Consider the oxidation of sulfur dioxide:
The Nitrogen Cycle
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...

