1) Students investigating chemical reactions conducted the experiment you see here. An antacid tablet was dropped in to plastic bag
containing 10 ml at 22°C distilled water. The bag was immediately
zipped closed and the chemical reaction proceeded until completion.
Cite evidence to confirm that this was a chemical reaction.

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.