Hydrogen reacts with chlorine to form hydrogen chloride HCl times g , ΔH_f=−92.3kJ/mol according to the reaction. cap h sub 2 of g plus Cl sub 2 times g rightarrow 2 HCl g Which statement is correct? Use ΔH_rxn=∑(ΔH_f_1products)−∑(ΔH_f_1reactants)
Answer
A
The enthalpy of the reaction is negative 184 point 6 kJ , and the reaction is exothermic.
B
The enthalpy of the reaction is 184 point 6 kJ , and the reaction is exothermic.
C
The enthalpy of the reaction is 184 point 6 kJ , and the reaction is endothermic.
D
The enthalpy of the reaction is negative 184 point 6 kJ , and the reaction is endothermic.
Explanation
The elements H₂(g) and Cl₂(g) have standard enthalpies of formation of 0 kJ/mol. The reaction forms 2 mol of HCl, so ΔH_rxn = 2(−92.3 kJ/mol) − 0 = −184.6 kJ. A negative reaction enthalpy means the reaction releases heat, so it is exothermic. The correct choice is A: the enthalpy is −184.6 kJ and the reaction is exothermic.
AI-written and checked against the verified answer.