A combustion reaction is carried out inside a thin metal cylinder that is submerged…
CHEMISTRY · Single correct · AP · Chemistry · Thermochemistry · Thermochemistry
Problem
A combustion reaction is carried out inside a thin metal cylinder that is submerged in a large water bath. After the reaction, the temperature of the water bath rises by 3.0∘C, while the temperature of the metal cylinder itself drops slightly. If the system is defined as ONLY the contents of the cylinder (reacting gases plus the metal cylinder), which of the following best describes the energy transfer involved?
(a) The process for the defined system is endothermic because the water bath gains heat from the surroundings, not from the system.
(b) The process for the defined system is neither endothermic nor exothermic because the cylinder’s temperature decreases while the water bath warms, so the effects cancel out.
(c) The process for the defined system is exothermic because heat flows from the system to the water bath, decreasing the energy of the system.
(d) The process for the defined system is endothermic because the cylinder cools down as it absorbs heat from the water bath.