Question

Understanding the definitions of heat and work 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 night.) From previous experiments, this chemical reaction is known to absorb 239. LJ of energy. The temperature of the water bath is monitored, and it is determined from this data that 214. kJ of heat flows out of the system during the reaction. Is the reaction exothermic or endothermic? exothermic endothermic О up Does the temperature of the water bath go up or down? neither Does the piston move in or out? out neither does won Does the gas mixture do work, or is work done work is done on neither How much work is done on (or by the gas mixture? Round your answer to 3 significant

Answer 1

- =) As the reaction is absorbing energy it is endothermie. The overall reaction takes energy and also gives back heat to the water bath. Overall, the amount of intake is more than distributed. So, there is a loss of heat from water bath. Temp. will go down - As P is constant, PV = nRT VET T of the reaction is also increase increased V will p iston will go up. =) the gars mixture does work Wa-pdv = - Pav ; AV = +ve =-ve = work done = (239 -214 ) = 25 kJ.