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 $1$atm. The cylinder is also submerged in a large insulated water bath. $($See sketch at right.$)$

The temperature of the water bath is monitored, and it is determined from this data that $158.kJ$ of heat flows out of the system during the reaction. The position of the piston is also monitored, and it is determined from this data that the system does $177.kJ$ of work on the piston during the reaction.

$\backslash$table$[[$Is the reaction exothermic or endothermic?,exothermic$]]$