Question #bbfd1 Chemistry Thermochemistry Enthalpy 1 Answer Michael · Media Owl Apr 30, 2015 2480.6 kJ required. For: #CH_(4(g))+2O_(2(g))rarrCO_(2(g))+2H_2O_((l))# #DeltaH_(comb)=-882.0"kJ"# So for the reverse reaction: #CO_(2(g))+2H_2O_((l))rarrCH_(4(g))+2O_(2(g))# #DeltaH=+882.0"kJ"# #[M_r]CH_4=16.0# So #16.0"g"# requires #882.0"kJ"# So #1"g"rarr882.0/16.0"kJ"# So #45"g"rarr(882.0)/(16.0)xx45=2480.0"kJ"# Answer link Related questions How are enthalpy changes expressed in chemical equations? How can enthalpy change be determined for an aqueous solution? How does enthalpy change with pressure? How do you calculate standard molar enthalpy of formation? Why is enthalpy a state function? Why is the enthalpy of formation of oxygen zero? Why is enthalpy a state function? Why can enthalpy not be measured directly? How does pressure affect enthalpy? How does enthalpy relate to internal energy? See all questions in Enthalpy Impact of this question 1900 views around the world You can reuse this answer Creative Commons License