Question

A mixture of gaseous reactants is put into a cylinder, where a chemical reaction turns them into gaseous products. The cylinder has a piston that moves in or out, as necessary, to keep a constant pressure on the mixture of 1atm. The cylinder is also submerged in a large insulated water bath. (See sketch at right.) From previous experiments, this chemical reaction is known to absorb 137.kJ of energy. The temperature of the water bath is monitored, and it is determined from this data that 235.kJ of heat flows out of the system during the reaction. is the reaction endothermic or exothermic? does the temperature of the water go up, down, or neither? does the piston move in or out? does the gas mixture do work or is the work done on it? how much work is done on or by the gas mixture? round to 3 sig figs

Answer 1

Since the amount of energy that flows out of the system is greater than the amount of energy absorbed by the system , so the net shell effect is ,

The energy is released during reaction, this means reaction is EXOTHERMIC .

Since the heat flows out from cylinder to water , this means the temperature of water INCREASES/GOES UP.

Since energy was absorbed by the system for reaction initially. As we know pressure will increase with increase in temperature . So, to keep the pressure constant at 1 atmosphere the piston will MOVE OUT.

Since the piston moves out, this means work is done BY THE SYSTEM .