Amass of gas has a volume of 4 m3, a temperature of 290 k, and an absolute pressure of 475 kpa. when the gas is allowed to expand to 6.5 m3, its new temperature is 277 k. what's the absolute pressure of the gas after expansion? a. 104.1 kpa b. 279.2 kpa c. 293.9 kpa d. 178.5 kpa

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.