ThermochemistryHard
Question
If x1, x2 and x3 are enthalpies of H - H, O = O and O - H bonds respectively, and x4 is the enthalpy of vaporisation of water, estimate the standard enthalpy of combustion of hydrogen.
Options
A.x1 + 
- 2x3 + x4
- 2x3 + x4B.x1 + - 2x3 - x4
- 2x3 - x4C.x1 + - x3 + x4
- x3 + x4D.2x3 - x1 - x4
- x4Solution
H2 (g) + 
O2 (g) → H2O (l) ; ᐃHcomb,H2
ᐃHcomb = ᐃHH − H +
ᐃHO = O - 2ᐃHO − H - ᐃHvap = x1 + 
-2x3 - x4
O2 (g) → H2O (l) ; ᐃHcomb,H2ᐃHcomb = ᐃHH − H +
ᐃHO = O - 2ᐃHO − H - ᐃHvap = x1 + -2x3 - x4Create a free account to view solution
View Solution FreeMore Thermochemistry Questions
Which of the following are true about resonance energy ?...The enthalpy of formation of methane(g) at constant pressure is −18,500 cal/mol at 27°C. The enthalpy of formation at co...Calculate the standard free energy change for the ionization HF(aq) → H+ (aq) + F– (aq) from the following data.HF(aq) →...Which of the following reaction(s) is/are endothermic?...At 300 K, the standard enthalpies of formation of C6H5COOH(s), CO2(g) and H2O(l) are −408, −393 and −286 kJ/mol, respect...