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The value of c V,m is always less than the value of c P,m. This difference is particularly notable in gases where values under constant pressure are typically 30% to 66.7% greater than those at constant volume. [4] All methods for the measurement of specific heat apply to molar heat capacity as well.
For example, Paraffin has very large molecules and thus a high heat capacity per mole, but as a substance it does not have remarkable heat capacity in terms of volume, mass, or atom-mol (which is just 1.41 R per mole of atoms, or less than half of most solids, in terms of heat capacity per atom).
In gas dynamics we are interested in the local relations between pressure, density and temperature, rather than considering a fixed quantity of gas. By considering the density ρ = M / V {\displaystyle \rho =M/V} as the inverse of the volume for a unit mass, we can take ρ = 1 / V {\displaystyle \rho =1/V} in these relations.
A gas is a substance which (a) at 50 °C (122 °F) has a vapor pressure greater than 300 kPa (43.51 PSI) or (b) is completely gaseous at 20 °C (68 °F) at a standard pressure of 101.3 kPa (14.69 PSI). Gases are assigned to one of three divisions division 2.1 Flammable gas; division 2.2 Non flammable, Non-toxic gas; division 2.3 Toxic gas
In the International System of Units (SI), the coherent unit for molar concentration is mol/m 3. However, most chemical literature traditionally uses mol/dm 3, which is the same as mol/L. This traditional unit is often called a molar and denoted by the letter M, for example: 1 mol/m 3 = 10 −3 mol/dm 3 = 10 −3 mol/L = 10 −3 M = 1 mM = 1 ...
Oxygen makes up only 20.95% of the volume of air, and only 23.20% of its mass. [13] The air-fuel ratios listed below are much higher than the equivalent oxygen-fuel ratios, due to the high proportion of inert gasses in the air.
The daily light integral (DLI) is the number of photosynthetically active photons (photons in the PAR range) accumulated in a square meter over the course of a day. It is a function of photosynthetic light intensity and duration (day length) and is usually expressed as moles of light (mol photons) per square meter (m −2) per day (d −1), or: mol·m −2 ·d −1.
For example, when the sun is more than about 60° above the horizon (<30°) the solar intensity is about 1000 W/m 2 (from equation I.1 as shown in the above table), whereas when the sun is only 15° above the horizon (=75°) the solar intensity is still about 600 W/m 2 or 60% of its maximum level; and at only 5° above the horizon still 27% of ...