Video Experimental Relacionado
Updated: Jul 7, 2026
08:14
Ammonia Synthesis at Low Pressure
Published on: August 23, 2017
Química ácido-base impulsada por electrones: transferencia de protones del cloruro de hidrógeno al amoníaco
Soren N Eustis1, Dunja Radisic, Kit H Bowen
1Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA.
Science (New York, N.Y.)
|February 16, 2008
Resumen
Las moléculas aisladas de amoníaco (NH3) y cloruro de hidrógeno (HCl) no forman cloruro de amonio (NH+4Cl-). Sin embargo, un exceso de electrones puede inducir el complejo NH3...HCl enlazado con hidrógeno para formar esta sal iónica.
Área de la Ciencia:
- Química Física es la química física.
- Química cuántica es la química cuántica.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- Las reacciones ácido-base generalmente ocurren en solución, formando sales como el cloruro de amonio.
- Las moléculas individuales de amoníaco (NH3) y cloruro de hidrógeno (HCl) no forman espontáneamente cloruro de amonio (NH + 4Cl-) en aislamiento.
Objetivo del estudio:
- Para investigar la interacción de un exceso de electrones con el complejo de enlaces de hidrógeno NH3...HCl.
- Para determinar si un exceso de electrones puede inducir la formación de la sal iónica NH+4Cl- a partir del complejo NH3...HCl.
Principales métodos:
- Se empleó espectroscopia de fotoelectrones aniónicos para estudiar el sistema.
- Se realizaron cálculos teóricos ab initio para respaldar los hallazgos experimentales.
Principales resultados:
- Se descubrió que un exceso de electrones induce la formación de la sal iónica NH+4Cl- a partir del complejo NH3...HCl.
- El ion negativo resultante, NH+4Cl-, puede describirse como un radical de Rydberg deformado (NH4) polarizado por un anión cloruro (Cl-).
Conclusiones:
- La presencia de un electrón en exceso es crucial para la formación de cloruro de amonio iónico a partir de moléculas aisladas de NH3 y HCl.
- Se propone un mecanismo que implica un estado de dipolo unido para la formación de sales inducida por electrones.
Videos de Conceptos Relacionados
01:20Titration of a Weak Base with a Strong Acid
The titration curve of a weak base like ammonia with a strong acid like hydrochloric acid is the mirror image of the titration curve of a weak acid with a strong base.
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
02:16Lewis Acids and Bases
This lesson delves into Lewis acids and bases in the context of the octet rule for electron-deficient compounds. Here, the concept is discussed, emphasizing the group 13 elements like boron or aluminium. Since group 13 elements possess three valence electrons, they form trivalent compounds with a sextet of electrons and a vacant orbital for the central atom. Consequently, these electron-deficient compounds accept electrons from other species to complete their octet in a chemical reaction. They...
02:33Lewis Acids and Bases
In 1923, G. N. Lewis proposed a generalized definition of acid-base behavior in which acids and bases are identified by their ability to accept or to donate a pair of electrons and form a coordinate covalent bond.
A coordinate covalent bond (or dative bond) occurs when one of the atoms in the bond provides both bonding electrons. For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. A coordinate covalent bond also results when...
A coordinate covalent bond (or dative bond) occurs when one of the atoms in the bond provides both bonding electrons. For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. A coordinate covalent bond also results when...
02:16Brønsted-Lowry Acids and Bases
In 1923, the Brønsted–Lowry definition of acids and bases was proposed by Johannes Brønsted and Thomas Lowry. According to this theory, a Brønsted acid is defined as a species that donates a proton in a chemical reaction and gets converted to its conjugate base. A Brønsted base is defined as a species that accepts a proton in a chemical reaction and gets converted into its conjugate acid. These transfers of protons are caused by the displacement of electrons in these reactions, which is...
02:58Bronsted-Lowry Acids and Bases
The acid-base reaction class has been studied for quite some time. In 1680, Robert Boyle reported traits of acid solutions that included their ability to dissolve many substances, to change the colors of certain natural dyes, and to lose these traits after coming in contact with alkali (base) solutions. In the eighteenth century, it was recognized that acids have a sour taste, react with limestone to liberate a gaseous substance (now known to be CO2), and interact with alkalis to form neutral...
01:07Acid Halides to Amides: Aminolysis
Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...