Answer to Question #247019 in Physical Chemistry for Reign

Question

Calculate the enthalpy change on the formation of methane gas from the elements, using the following data at 25 degrees celsius and one bar pressure:
Heat of Combustion = 393.51 kj/mol
Heat of formation of Water Vapor = 241.82 kj/mol
Heat of combustion of methane gas to liquid water = 890.36 kj/mol
Heat of vaporization of water = 583.91 kj/mol

Answer 1

∆H = m x s x ∆T

(393.51+890.36)-(583.91+241.82)

= 1283.87-825.73

= 458.14

458.14×298

= 136525.72kJ/mol