Search results
Results from the WOW.Com Content Network
The standards below are two examples of commonly used and cited publications that provide a composition for standard dry air: ISO TR 29922-2017 provides a definition for standard dry air which specifies an air molar mass of 28,965 46 ± 0,000 17 kg·kmol-1. [2] GPA 2145:2009 is published by the Gas Processors Association.
They range from those of water at very low concentrations approaching 0% HCl to values for fuming hydrochloric acid at over 40% HCl. [ 31 ] [ 32 ] [ 33 ] Hydrochloric acid as the binary (two-component) mixture of HCl and H 2 O has a constant-boiling azeotrope at 20.2% HCl and 108.6 °C (381.8 K; 227.5 °F).
Consequently, if a liquid has dynamic viscosity of n centiPoise, and its density is not too different from that of water, then its kinematic viscosity is around n centiStokes. For gas, the dynamic viscosity is usually in the range of 10 to 20 microPascal-seconds, or 0.01 to 0.02 centiPoise. The density is usually on the order of 0.5 to 5 kg/m^3.
When expressed in percent, it is known as the mole percent or molar percentage (unit symbol %, sometimes "mol%", equivalent to cmol/mol for 10 −2). The mole fraction is called amount fraction by the International Union of Pure and Applied Chemistry (IUPAC) [ 1 ] and amount-of-substance fraction by the U.S. National Institute of Standards and ...
A more convenient laboratory method involves the (reversible) dehydration of nitrous acid by HCl [4] HNO 2 + HCl → H 2 O + NOCl. By the direct combination of chlorine and nitric oxide; This reaction reverses above 100 °C. Cl 2 + 2 NO → 2 NOCl. By reduction of nitrogen dioxide with hydrogen chloride: [5] 2NO 2 + 4 HCl → 2NOCl + 2H 2 O + Cl 2
Small amounts of hydrogen chloride for laboratory use can be generated in an HCl generator by dehydrating hydrochloric acid with either sulfuric acid or anhydrous calcium chloride. Alternatively, HCl can be generated by the reaction of sulfuric acid with sodium chloride: [17] NaCl + H 2 SO 4 → NaHSO 4 + HCl↑. This reaction occurs at room ...
Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. [1] For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase : [2]
Mass fraction can also be expressed, with a denominator of 100, as percentage by mass (in commercial contexts often called percentage by weight, abbreviated wt.% or % w/w; see mass versus weight). It is one way of expressing the composition of a mixture in a dimensionless size ; mole fraction (percentage by moles , mol%) and volume fraction ...