Practice Problem: Fick's First Law 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 3.8-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 4.9 and 0.66 kg/m3 (kilogram of hydrogen per cubic meter of palladium), and that steady-state conditions have been attained

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size