The heat combustion of acetylene, C2H2(g), at 25°C, is –1299 kJ/mol. At this temperature, ΔHvalues for CO2(g) and H2O(l) are –393 and –286 kJ/mol, respectively. Calculate ΔHfor acetylene.

Respuesta :

 The enthalpy of the reaction in an aqueous solution can be determined by taking the difference between the summation of enthalpies of the products multiplied to their respective stoichiometric coefficient and the summation of enthalpies of the reactants multiplied to their respective  stoichiometric coefficient. The equation is 2C2H2 + 5O2 >>> 4CO2 + 2H2O. Hence the enthalpy calculation is delta H = –393*4 + 2*-286 -(-1299*2) = 454 kJ

Using the information in the table to the right, calculate the enthalpy of combustion of each of the following substances:  acetylene:       ⇒ -1,256 kJ/mol ethanol:       ⇒ -1,277 kJ/mol  This is from a different problem on Edgenuit.y but hope this helps someone who couldn’t find the answer like me.