Related Questions

Determine the diffusivity of CO2 in a gas mixture having the composition: CO2: 28.5 %, O2: 15%, N2: 56.5%, The gas mixture is at 273 k and 1.2 * 105 Pa. The binary diffusivity values are given as: (at 273 K) D12 P = 1.874 m2 Pa/sec D13 P = 1.945 m2 Pa/sec D23 P = 1.834 m2 Pa/sec
Find the diffusivity through slab if N flux of A 4 mol/sq.m sec, concentration difference is 2mol/cu.m and distance is 3 m.
Find the flux of A ( xA= 0.2) if Total flux is 5 mol/sq.m sec and J flux of A is 2 mol/sq.m sec.
Find J flux of A ( xA = 0.5) if the total N flux is 6 mol/sq.m sec and N flux of A is 3 mol/sq.m sec.
The concentration of oxygen at the inner surface of the vessel is maintained at a level C depending on the pressure in the vessel, while the concentration at the outer surface is reduced to zero by the escape of oxygen to the surroundings. A steady state will eventually be reached when the concentration everywhere reaches a constant value. Provided D is independent of concentration there will be a single concentration gradient in the wall and the thickness of the wall is L, the flux is given by________________
The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________
Find the change in concentration for a steady state equimolar counter diffusion if D(AB)= 6 sq.m/sec, the change in distance is 2 m and the N flux of A is 5 mol/sq.m sec.
Find the activated diffusivity of carbon if energy of activation is 6 kJ; the value of constant diffusivity is 2.5 sq.m/sec. (Hint: the value of exponential of (-6/RT) is 2.55)
A stream of air at 100 kPa pressure and 300 K is flowing on the top surface of a thin flat sheet of solid naphthalene of length 0.2 m with a velocity of 20 m/sec. The other data are: Mass diffusivity of naphthalene vapor in air = 6 * 10 –6 m2/sec Kinematic viscosity of air = 1.5 * 10 –5 m2.sc Concentration of naphthalene at the air-solid naphthalene interface = 1 * 10 – 5 kmol/m3 Calculate the overage mass transfer coefficient over the flat plate. Note: For heat transfer over a flat plate, convective heat transfer coefficient for laminar flow can be calculated by the equation. Nu = 0.664 ReL1/2 Pr1/3 you may use analogy between mass and heat transfer.
From the reaction, Methane –> Carbon + 2(Hydrogen molecule) find the ratio of N Flux of A to the Total N flux( A+B); Given N Flux of B =-2 N flux of A.