The purification of hydrogen gas is possible by diffusion through a thin palladium sheet. calculate the number of kilograms of hydrogen that pass per hour (in kg/h) through a 3.0-mm thick sheet of palladium having an area of 0.25 m2 at 500°c. assume a diffusion coefficient of 6.0 x 10-8 m2/s, that the concentrations at the high- and low-pressure sides of the plate are 3.7 and 0.88 kg/m3 (kilogram of hydrogen per cubic meter of palladium), and that steady-state conditions have been attained.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

The filament of an incandescent lamp has a temperature of 2000k. calculate the fraction of radiation emitted in the visible light band if the filament is approximated as blackbody

Calculate the bore of a cylinder that has a stroke of 18 inches and an extension time of 6 seconds at a flow rate of 4 gal/min.