Question

For each equation listed below, determine the H and type of reaction (endothermic or exothermic)

a) C(s) + O2(g) ⟶ CO2(g) + 393.51 kJ
b) CH4(g) + 2O2(g) ⟶ CO2(g) + H2O(l) + 890.13 kJ
c) CaCO3(s) + 176 kJ ⟶ CaO(s) + CO2(g)
d) H2O(g) ⟶ H2O(l) + 44.02 kJ

Answer 1

a) The reaction C(s) + O2(g) ⟶ CO2(g) + 393.51 kJ is an exothermic reaction. b) The reaction CH4(g) + 2O2(g) ⟶ CO2(g) + H2O(l) + 890.13 kJ is also an exothermic reaction. c) The reaction CaCO3(s) + 176 kJ ⟶ CaO(s) + CO2(g) is an endothermic reaction. d) The reaction H2O(g) ⟶ H2O(l) + 44.02 kJ is an exothermic reaction.

Step-by-step explanation:

a) The reaction C(s) + O2(g) ⟶ CO2(g) + 393.51 kJ is an exothermic reaction because heat is being released. The positive value for the enthalpy change indicates that the reaction is exothermic.

b) The reaction CH4(g) + 2O2(g) ⟶ CO2(g) + H2O(l) + 890.13 kJ is also an exothermic reaction because heat is being released. The positive value for the enthalpy change indicates that the reaction is exothermic.

c) The reaction CaCO3(s) + 176 kJ ⟶ CaO(s) + CO2(g) is an endothermic reaction because heat is being absorbed. The positive value for the enthalpy change indicates that the reaction is endothermic.

d) The reaction H2O(g) ⟶ H2O(l) + 44.02 kJ is an exothermic reaction because heat is being released. The positive value for the enthalpy change indicates that the reaction is exothermic.