Search results
Results from the WOW.Com Content Network
The SI unit of volumetric heat capacity is joule per kelvin per cubic meter, J⋅K −1 ⋅m −3. The volumetric heat capacity can also be expressed as the specific heat capacity (heat capacity per unit of mass, in J⋅K −1 ⋅kg −1) times the density of the substance (in kg/L, or g/mL). [1] It is defined to serve as an intensive property.
For gases, departure from 3 R per mole of atoms is generally due to two factors: (1) failure of the higher quantum-energy-spaced vibration modes in gas molecules to be excited at room temperature, and (2) loss of potential energy degree of freedom for small gas molecules, simply because most of their atoms are not bonded maximally in space to ...
The molar mass of atoms of an element is given by the relative atomic mass of the element multiplied by the molar mass constant, M u ≈ 1.000 000 × 10 −3 kg/mol ≈ 1 g/mol. For normal samples from Earth with typical isotope composition, the atomic weight can be approximated by the standard atomic weight [2] or the conventional atomic weight.
From this table we see that the number of hydrogen and chlorine atoms on the product's side are twice the number of atoms on the reactant's side. Therefore, we add the coefficient "2" in front of the HCl on the products side, to get the equation to look like this: Mg + 2 HCl → MgCl 2 + H 2. and the table reflects that change:
Since the molar heat capacity of a substance is the specific heat c times the molar mass of the substance M/N its numerical value is generally smaller than that of the specific heat. Paraffin wax, for example, has a specific heat of about 2500 J⋅K −1 ⋅kg −1 but a molar heat capacity of about 600 J⋅K −1 ⋅mol −1.
The term molality is formed in analogy to molarity which is the molar concentration of a solution. The earliest known use of the intensive property molality and of its adjectival unit, the now-deprecated molal, appears to have been published by G. N. Lewis and M. Randall in the 1923 publication of Thermodynamics and the Free Energies of Chemical Substances. [3]
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 ...
This can be used to quantify the mass transfer between phases, immiscible and partially miscible fluid mixtures (or between a fluid and a porous solid [2]). Quantifying mass transfer allows for design and manufacture of separation process equipment that can meet specified requirements, estimate what will happen in real life situations (chemical ...