In a closed container, the gas-phase reaction P(g)+Q(g)→R(g)+S(g)P(g) + Q(g) \rightarrow R(g) + S(g)P(g)+Q(g)→R(g)+S(g) takes place.
The total energy required to break all the chemical bonds in the reactants P P\,P and Q Q\,Q is 1850 kJ mol-1. The total energy released when new bonds are formed to produce R R\,R and S S\,S is 1610 kJ mol-1.
Which of the following correctly identifies the temperature change of the surroundings, the enthalpy change (ΔH\Delta HΔH) of the reaction, and the thermodynamic classification of this process?
The temperature of the surroundings decreases, ΔH=+240 kJ mol−1\Delta H = +240\text{ kJ mol}^{-1}ΔH=+240 kJ mol−1, and the reaction is endothermic.
The temperature of the surroundings increases, ΔH=−240 kJ mol−1\Delta H = -240\text{ kJ mol}^{-1}ΔH=−240 kJ mol−1, and the reaction is exothermic.
The temperature of the surroundings decreases, ΔH=−240 kJ mol−1\Delta H = -240\text{ kJ mol}^{-1}ΔH=−240 kJ mol−1, and the reaction is exothermic.
The temperature of the surroundings increases, ΔH=+240 kJ mol−1\Delta H = +240\text{ kJ mol}^{-1}ΔH=+240 kJ mol−1, and the reaction is endothermic.
