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United States – NEC 2008 Table 250.122 ... United States – NFPA, IEEE STD 80, IEEE STD 80, NFPA 496, NFPA 70 [21]
1,1,1,2-Tetrafluoroethane (also known as norflurane (), R-134a, Klea 134a, Freon 134a, Forane 134a, Genetron 134a, Green Gas, Florasol 134a, Suva 134a, HFA-134a, or HFC-134a) is a hydrofluorocarbon (HFC) and haloalkane refrigerant with thermodynamic properties similar to R-12 (dichlorodifluoromethane) but with insignificant ozone depletion potential and a lower 100-year global warming ...
Being a good solvent for many materials (such as grease and tar), carbon tetrachloride was widely used as a cleaning fluid for nearly 70 years. It is nonflammable and nonexplosive and did not leave any odour on the cleaned material, unlike gasoline, which was also used for cleaning at the time. It was used as a "safe" alternative to gasoline.
Selenium pollution might impact some aquatic systems and may be caused by anthropogenic factors such as farming runoff and industrial processes. [100] People who eat more fish are generally healthier than those who eat less, [ 101 ] which suggests no major human health concern from selenium pollution, although selenium has a potential effect on ...
The standard enthalpy change of combustion, ΔH° c, expressed per mole of ammonia and with condensation of the water formed, is −382.81 kJ/mol. Dinitrogen is the thermodynamic product of combustion: all nitrogen oxides are unstable with respect to N 2 and O 2, which is the principle behind the catalytic converter.
Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion. Dichloromethane is not classified as an ozone-depleting substance by the Montreal Protocol. [43] The US Clean Air Act does not regulate dichloromethane as an ozone depleter. [44] Dichloromethane has been classified as a very short-lived substance (VSLS).
Nitrogen dioxide is a reddish-brown gas with a pungent, acrid odor above 21.2 °C (70.2 °F; 294.3 K) and becomes a yellowish-brown liquid below 21.2 °C (70.2 °F; 294.3 K). It forms an equilibrium with its dimer , dinitrogen tetroxide ( N 2 O 4 ), and converts almost entirely to N 2 O 4 below −11.2 °C (11.8 °F; 261.9 K).
Ethanol-water mixtures have less volume than the sum of their individual components at the given fractions. Mixing equal volumes of ethanol and water results in only 1.92 volumes of mixture. [76] [81] Mixing ethanol and water is exothermic, with up to 777 J/mol [82] being released at 298 K. Hydrogen bonding in solid ethanol at −186 °C