Engineering, 07.12.2019 01:31 EvoBruh3273

Water in a test tube (1 cm diameter) is held at a constant temperature of 293 k. the total pressure of air (assume dry) is 1 atm and the temperature is 293 k. the vapor pressure of water at 293k is 17.54 mm hg or 0.0231 atm. water in the test tube evaporates at a rate of 4 × 10-7 ml/s when the distance between the surface of water and the opening of the test tube is l = 10 cm.

a. determine the mass transfer coefficients kc, kg, ky.

b. if l is reduced to 2 cm, what are the new values for the mass transfer coefficients?

c. if nb=0, show that kg=dabp/(lrt)(pb)lm where (pb)lm=(pb2-pb1)/ln(pb2/pb1) and dab is the diffusivity of water vapor in air, t is temperature (k) and r is the ideal gas law constant (= 82.057 cm3 ∙atm/g mol∙k)

d. determine the sherwood number, shc = kcl/dab when l = 2 cm. e. what would be the new sherwood number and mass transfer coefficients if the water in the test tube is directly exposed to the flowing air (or l = 0 cm)?

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Water in a test tube (1 cm diameter) is held at a constant temperature of 293 k. the total pressure...