Areaction inside a cylindrical container with a movable piston causes the volume to change from 12.0 l to 18.0 l while the pressure outside the container remains constant at 0.975 atm. (the volume of a cylinder is v = πr 2h), where h is the height; 1 l atm = 101.325 j) a. what is the value in joules of the work w done during the reaction?

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.

It is really hard for me right know

What component of earth’s atmosphere exists entirely as a result of photosynthesis?