Dr. Harris Chemistry 105 Practice Exam 1 Isotope Atomic Number
... Why do atoms exhibit discontinuous (line) spectra when they emit light? Why can’t an atom emit any wavelength of light? Energy is quantized. Emission is due to specific transitions between ground and excited states. 18. Refer to the activity series in chapter 10. For the single replacement reactions ...
... Why do atoms exhibit discontinuous (line) spectra when they emit light? Why can’t an atom emit any wavelength of light? Energy is quantized. Emission is due to specific transitions between ground and excited states. 18. Refer to the activity series in chapter 10. For the single replacement reactions ...
Unit 14.1 REDOX Reactions Objectives REDOX Reactions
... • REDOX reactions involve the transfer of electrons from one species to another. • A REDOX reaction involves both an oxidation of one species and a reduction of another. • REDOX reactions can be used to convert chemical potential energy into electrical energy. ...
... • REDOX reactions involve the transfer of electrons from one species to another. • A REDOX reaction involves both an oxidation of one species and a reduction of another. • REDOX reactions can be used to convert chemical potential energy into electrical energy. ...
Unit 13 - Electrochemistry
... the oxidizing agent. - Single replacement and combustion reactions are redox reactions, double replacement is not a redox reaction. ...
... the oxidizing agent. - Single replacement and combustion reactions are redox reactions, double replacement is not a redox reaction. ...
Dr. Harris Chemistry 105 Practice Exam 1 Isotope Atomic Number
... 300 nm, and assuming that the emission rate is constant, how many photons are emitted per minute? ...
... 300 nm, and assuming that the emission rate is constant, how many photons are emitted per minute? ...
Microbial Metabolism
... Modes of E Conservation-ATP • Fermentation: in which redox reaction ocurs WITHOUT a terminal electron acceptor (couple oxiation with subsequent reduction of an organic ...
... Modes of E Conservation-ATP • Fermentation: in which redox reaction ocurs WITHOUT a terminal electron acceptor (couple oxiation with subsequent reduction of an organic ...
Photoredox catalysis
Photoredox catalysis is a branch of catalysis that harnesses the energy of visible light to accelerate a chemical reaction via a single-electron transfer. This area is named as a combination of ""photo-"" referring to light and redox, a condensed expression for the chemical processes of reduction and oxidation. In particular, photoredox catalysis employs small quantities of a light-sensitive compound that, when excited by light, can mediate the transfer of electrons between chemical compounds that otherwise would not react. Photoredox catalysts are generally drawn from three classes of materials: transition-metal complexes, organic dyes and semiconductors. While each class of materials has advantages, soluble transition-metal complexes are used most often.Study of this branch of catalysis led to the development of new methods to accomplish known and new chemical transformations. One attraction to the area is that photoredox catalysts are often less toxic than other reagents often used to generate free radicals, such as organotin reagents. Furthermore, while photoredox catalysts generate potent redox agents while exposed to light, they are innocuous under ordinary conditions Thus transition-metal complex photoredox catalysts are in some ways more attractive than stoichiometric redox agents such as quinones. The properties of photoredox catalysts can be modified by changing ligands and the metal, reflecting the somewhat modular nature of the catalyst.While photoredox catalysis has most often been applied to generate known reactive intermediates in a novel way, the study of this mode of catalysis led to the discovery of new organic reactions, such as the first direct functionalization of the β-arylation of saturated aldehydes. Although the D3-symmetric transition-metal complexes used in many photoredox-catalyzed reactions are chiral, the use of enantioenriched photoredox catalysts led to low levels of enantioselectivity in a photoredox-catalyzed aryl-aryl coupling reaction, suggesting that the chiral nature of these catalysts is not yet a highly effective means of transmitting stereochemical information in photoredox reactions. However, while synthetically useful levels of enantioselectivity have not been achieved using chiral photoredox catalysts alone, optically-active products have been obtained through the synergistic combination of photoredox catalysis with chiral organocatalysts such as secondary amines and Brønsted acids.