1. Chilling effects the endothermic reaction between ammonium thiocyanate and barium hydroxide
November 2016
rsc.li/EiC616ec

2. the 2nd law of thermodynamics
energy
spreads
out
the 2nd law of thermodynamics

3. Cup of coffee with beans by Petr Kratochvil [Public domain], via Wikimedia Commons
Et baal.jpg by Einar Helland Berger (Own work) [CC BY-SA 2.5 ( via Wikimedia Commons

4. a process that releases heat
exothermic
a process that releases heat
reactants
energy DH
products
Et baal.jpg By Einar Helland Berger (Own work) [CC BY-SA 2.5 ( via Wikimedia Commons

5. energy spreads out: entropy increases
NH3
NH3
NH3
energy spreads out: entropy increases
NH3
NH4+
SCN-
OH-
OH-
NH4+
SCN-
NH4+
H2O
SCN-
H2O
Ba2+
Ba2+
H2O
SCN-
OH-
OH-
SCN-
NH4+
SCN-
SCN-
Ba2+
SCN-
Ba2+
H2O
more heat energy, but contained in ordered solid
less heat energy,
but spread out more in liquid and gas: disordered