Question

Write the formation reactions including energy as a term for the following substances. Identify which is the least stable and which is the most stable compounds based on their molar enthalpies of formation. a) ammonium nitrate b) ethanol c) silver chloride. Please show your work, use dimensional analysis if possible. /4

Answer 1

formation reaction for

a) ammonium nitrate :

N2 (g) + 2 H2 (g) + 3/2 O2 (g) --------------------> NH4NO3 (s) , Hf _NH4NO3 (s) = - 365.6 kJ/mol

b) ethanol

2 C (s) + 3 H2 (g) + 1/2 O2 (g) ---------------------> C2H5OH (l) ,     Hf _C2H5OH (l) = - 277.7 kJ/mol

c) silver chloride

Ag (s) + 1/2 Cl2 (g) ---------------------> AgCl (s)        ,        Hf _AgCl (s) = - 127.1 kJ/mol

the energy liberation is more that is most stable.

most stabel NH4NO3

least stable AgCl