Thermochemistry

 

 50) mw = 60.0 g H2O          Ti = 23.0°C          m = 3.88 g NH4NO3

       cw = 4.18 J/g•K             Tf = 18.4°C

 

       NH4NO3(s) NH4+(aq) + NO3-(aq)

               

      ql = mcwΔT

      ql = 63.88 g x 4.18 J/gK x (23.0°C - 18.4°C) = 1.2 x 103 J

       

      ΔH = q/n = 1.2 x 103 J/3.88 g NH4NO3 x 1 kJ/103 J x 80.06 g NH4NO3/1 mol NH4NO3 = 25 kJ/mol NH4NO3