Oxidation Numbers
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk in Survival Guide to General Chemistry, 2019
Use the given equation or write the correct balanced equation; then analyze the redox reaction using steps (1) through (4). Calcium metal reacts with water to produce calcium hydroxide solid plus hydrogen gas.Lead metal reacts with aqueous sulfuric acid to form lead (IV) sulfate solid plus hydrogen gas.Iron metal reacts with oxygen gas to form iron (III) oxide.Acetylene gas (C2H2) burns in oxygen gas to form carbon dioxide plus water.Iron metal reacts with aqueous silver nitrate to form aqueous iron (II) nitrate plus silver metal.
11C, 13N, and 15O Tracers
Garimella V. S. Rayudu, Lelio G. Colombetti in Radiotracers for Medical Applications, 2019
Other 11C-labeled synthetic precursors which have been made are phosgene19,20 and acetylene, but these have yet to be used extensively for the preparation of more complex organic molecules, although they have great potential. Cramer and Kistiakowski21 first made 11C-acetylene by hydrolyzing 11C-BaC2 which they had prepared from Ba11CO3. Nickles et al.,22 by an adaptation of this method, have also made 11C-acetylene in 60% yield without added carrier. Myers23 and Vaalberg et al.24 have also made 11C-acetylene via the helium-3 or proton irradiation of calcium carbide which on hydrolysis yields 11C-acetylene. Crouzel et al.25 have also made 11C-acetylene by pyrolysis of 11C-methane, but this method requires a lot of auxiliary equipment.
Metallic poisons *
Bev-Lorraine True, Robert H. Dreisbach in Dreisbach’s HANDBOOK of POISONING, 2001
Phosphorus exists in several allotropic forms, the most important of which are red phosphorus, a granular, nonabsorbed, and nonpoisonous form; and white phosphorus, a yellow, waxy, water-insoluble and fat-soluble, highly poisonous form that will burn on contact with air. Red phosphorus is sometimes contaminated with white phosphorus. The striking surface of a safety match contains 50% red phosphorus. White phosphorus is used in rodent and insect poisons, fireworks, and fertilizer manufacture. The action of water or acids on metals will liberate phosphine (hydrogen phosphide, PH3) if phosphorus is present as a contaminant. Phosphine may also be present in acetylene. Phosphides, which are used as rat poisons, release phosphine on contact with water. Phosphorus sesquisulfide (tetraphosphorus trisulfide) has low toxicity. The heads of 20 large wooden matches contain 220 mg phosphorus sesquisulfide.
Arrested Acetylene-Induced Pulmonary and Testicular Toxicity in Rats Through Treatment With Polyphenols
Published in Drug and Chemical Toxicology, 2023
Tanitoluwa O. Oluwabayo, Afolabi C. Akinmoladun, Afolabi A. Akindahunsi
Acetylene (molecular formula: C2H2) is a colorless, extremely flammable gas used in combination with oxygen to generate oxyacetylene, a fuel for making hot flame that can weld and cut metals in industries. Acetylene is odorless when made from the hydrolysis of 100% pure calcium carbide, but it has a stifling garlic stench when it is made from impure calcium carbide which is the type mainly utilized in the Nigerian welding industry (Ibeh et al. 2016). Impurities such as arsenic, phosphorus, and sulfur are often found in commercial-grade calcium carbide, and on reaction with water yield arsine, phosphine, ammonia, hydrogen sulfide, and other compounds which are known to be carcinogenic and genotoxic (Onwukwe et al. 2018). Exposure to this flame for an extended period has been linked to hemolysis and oxidative stress, and noncompliance of many workers to safety measures like the use of personal protective equipment results in an increased level of exposure to the gas. The problem is exacerbated by a lack of data on the toxic profile of this industrial gas which limits the search for appropriate measures to ameliorate its toxic effects.
Heavy metals in edible salt from Ghana with special reference to potential human health risk
Published in Toxin Reviews, 2021
The total concentrations of Pb, Cd, Co, and Mn in the digested samples were determined using flame atomic absorption spectrometry (Shimadzu AA-7000, Kyoto, Japan). The operation condition for the acetylene gas flow rate was set to 1.5 l/min. Standard solutions of the respective metallic salts (1000 ppm) were used to obtain calibration curve. A recovery study was performed by spiking already analyzed samples with various concentrations of metals and taken through the digestion process for analysis. The recoveries for the studied metals ranged 92–102% and the relative standard deviations for the analyzed metals were below 12%.
Composition of aerosols from thermal degradation of flavors used in ENDS and tobacco products
Published in Inhalation Toxicology, 2022
Philip J. Kuehl, Jacob D. McDonald, Derek T. Weber, Andrey Khlystov, Matthew A. Nystoriak, Daniel J. Conklin
Vanillin (4-hydroxy-3-methoxybenzaldehyde) degradation products at both temperatures included benzone and oxidized benzenes. At low temperature, the most abundant products were acetylene, ethene, and isobutane, indicating carbon-carbon breaks and dehydrogenation reactions occurring during the thermal heating process. The high temperature formed primarily oxidized aromatics, including vanillic acid. Similar to the products of other flavorants, the degradation profile also included lower concentrations of carbonyls, alkylated aromatic compounds, and PAHs at both temperatures.
Related Knowledge Centers
- Carbide
- Chemical Compound
- Hydrocarbon
- Phosphine
- Potassium
- Potassium Carbonate
- Chemical Nomenclature
- Divinyl Sulfide
- Saturated & Unsaturated Compounds
- Hydrogen