8.115 part b

[Garret G 2F]

If we know that ~14.73 moles of H2 were burned in a combustion reaction and that the temperature (298K) and Volume (30L) did not change, just the pressure (16 atm to 4 atm), How do we find the heat given off in the reaction? Do we need to look up the enthalpy of this reaction?

[Andrea ORiordan 1L]

For this problem, you use the value from a table of enthalpies of combustion (I believe in Appendix 2A). The enthalpy of combustion for H2 is -286kJ/mol. Multiplying that by 14.7 moles, you get -4.20*10^3 kJ.