How do you calculate the unit of diffusivity?
Thermal diffusivity is measured in the area per unit time, i.e., meters square per second or feet square per second. Considering, the units of thermal conductivity as W/m⋅K , density being kg/m³ , and specific heat as J/kg⋅K , we get: (W/m K) / ((kg/m³) × (J/kg⋅K)) = m²/s .
What is K in diffusion?
D0 is the maximal diffusion coefficient (at infinite temperature; in m2/s), EA is the activation energy for diffusion (in J/mol), T is the absolute temperature (in K), R ≈ 8.31446 J/(mol⋅K) is the universal gas constant.
What is the diffusion coefficient of nacl?
The diffusion coefficient of Na+ and Cl- ions in water, extracted from relevant data in Table 2, are found to be 1.33 x 10-5 cm2/s and 2.03 x 10-5 cm2/s respectively.
What is Fick’s Law of diffusion equation?
Fick’s First Law Movement of solute from higher concentration to lower concentration across a concentration gradient. J = − D d φ d x. Where, J: diffusion flux. D: diffusivity.
What is the concentration of nitric acid?
Dilute nitric acid may be concentrated by distillation up to 68% acid, which is a maximum boiling azeotrope. In the laboratory, further concentration involves distillation with either sulfuric acid or magnesium nitrate, which serve as dehydrating agents.
What is the density of red fuming nitric acid?
Red fuming nitric acid, or RFNA, contains substantial quantities of dissolved nitrogen dioxide (NO 2) leaving the solution with a reddish-brown color. Due to the dissolved nitrogen dioxide, the density of red fuming nitric acid is lower at 1.490 g/cm 3 .
What is the hnoa-air diffusion coefficient of 298 K?
The HNOa-air diffusion coefficient = 0.11810.003011^”‘ (n = 7) for T = 298 K and P = l atm. It exhibited no dependence on relative humidity over the range 5-95 %. Key word index: Nitric acid, relative humidity, diffusion coefficient, duder tube.
What is the freezing point of nitric acid?
CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 4-78 The freezing point curve for aqueous solutions of nitric acid has two maxima corresponding to melting points for the two hydrates of nitric acid: the monohydrate (77.77 wt% acid) at -37.62 °C and the trihydrate (58.83 wt% acid) at -18.47 °C. Local minima occur at 32, 71, and 91 wt % acid.