Search results
Results from the WOW.Com Content Network
, , and are the usual agents of a chemical equation with coefficients and is a positive or negative numerical value, which generally has units of kJ/mol. Another equation may include the symbol E {\displaystyle E} to denote energy; E {\displaystyle E} 's position determines whether the reaction is considered endothermic (energy-absorbing) or ...
Apart from these remarkable solutions, much of the chemistry in liquid ammonia can be classified by analogy with related reactions in aqueous solutions. Comparison of the physical properties of NH 3 with those of water shows NH 3 has the lower melting point, boiling point, density, viscosity , dielectric constant and electrical conductivity .
NH2 or similar may refer to: Azanide (chemical formula NH − 2) Amino radical (chemical formula NH • 2) Nitrenium ion (chemical formula NH + 2) Primary amide group (chemical formula -NH 2) National Harbor–Alexandria Line (Route NH2), a WMATA bus line between Alexandria, Virginia and Prince George's County, Maryland; National Highway 2 (India)
Ammonium is a modified form of ammonia that has an extra hydrogen atom. It is a positively charged molecular ion with the chemical formula NH + 4 or [NH 4] +.It is formed by the addition of a proton (a hydrogen nucleus) to ammonia (NH 3).
For endothermic (heat-absorbing) processes, the change ΔH is a positive value; for exothermic (heat-releasing) processes it is negative. The enthalpy of an ideal gas is independent of its pressure or volume, and depends only on its temperature, which correlates to its thermal energy. Real gases at common temperatures and pressures often ...
According to the first law of thermodynamics, the enthalpy change in a system due to a reaction at constant pressure is equal to the heat absorbed (or the negative of the heat released), which can be determined by calorimetry for many reactions. The values are usually stated for reactions with the same initial and final temperatures and ...
The SI unit for heat capacity of an object is joule per kelvin (J/K or J⋅K −1). Since an increment of temperature of one degree Celsius is the same as an increment of one kelvin, that is the same unit as J/°C. The heat capacity of an object is an amount of energy divided by a temperature change, which has the dimension L 2 ⋅M⋅T −2 ...
Std enthalpy change of fusion, Δ fus H o +5.653 kJ/mol Std entropy change of fusion, Δ fus S o +28.93 J/(mol·K) Std enthalpy change of vaporization, Δ vap H o +23.35 kJ/mol at BP of −33.4 °C Std entropy change of vaporization, Δ vap S o +97.41 J/(mol·K) at BP of −33.4 °C Solid properties Std enthalpy change of formation, Δ f H o ...