Consider the following reaction which occurs at constant temperature and pressur
ID: 599073 • Letter: C
Question
Consider the following reaction which occurs at constant temperature and pressure:2 NO(g) + 2 H2(g) N2(g) + 2 H2O(g) H = -664.4 kJ
Which has the higher enthalpy, 2 NO(g) + 2 H2(g) or N2(g) + 2 H2O(g)?
2 NO(g) + 2 H2(g)
N2(g) + 2 H2O(g)
Without referring to tables indicate which of each of the pairs of choices below has the higher enthalpy:
(a)
carbon dioxide and water resulting from the complete combustion of one mole of gasoline
1 mole of gasoline mixed with a stoichiometrically equivalent amount of oxygen
(b)
1 mol of H2O(l) at 0 oC
1 mol of H2O(s) at 0 oC
(c)
1 mol of N2(g) at -100 oC
1 mol of N2(l) at -100 oC
(d)
1 mol of H2(g) and 0.5 mol of O2(g) at 25 oC
1 mol of H2O(g) at 25 oC
Explanation / Answer
(c) 1 mol of N2(g) at -100 oC 1 mol of N2(l) at -100 oC