What is the mass of solid dissolved per unit volume of liquid called?

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

What about a rubber band, can it change its shape? is it a solid?

James joule carefully measured the difference in temperature of the water at the top and bottom of a waterfall. why did he expect a difference