Ammonium nitrate is used in cold packs to “ice” injuries.
The thermochemical equation is:
NH_4NO_3(s)\longrightarrow NH_4^+(aq) + NO_3^–(aq)
\Delta H_{rxn}
= 26.8 kJ
What is the final temperature of a solution when 24.7 g of
NH_4NO_3
dissolves in 165 g of water in a
coffee cup calorimeter? The initial temperature is 21.6 ºC. (The mass of the
solution is the sum of the masses of solute and solvent.) The heat capacity of
the solution is 4.184 J/ (g•ºC)