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 page 2 of 3 through a 6 mm thick sheet of palladium having an area of 0.25 m2 at 600°c. assume a diffusion coefficient of 1.7 × 10-8 m2 /s, that the concentrations at the high and low pressure sides of the plates are 2.0 and 0.4 kg/m3 of hydrogen per cubic meter of palladium, and that steady state conditions have been attained.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented