Thermochemical Equations

1
Thermochemical Equations

• Balanced equation
• Includes energy term (Absorbs, Releases)
• Never (-) in an equation

Chemistry Benchmark 3
2
?E

• Endothermic
• Heat is absorbed written as a reactant on the
  left side
• Melting, Boiling

energy heat
3
?E -

• Exothermic
• Heat is released written as a product on the
  right side
• Freezing, Condensing

Hg(l) ? Hg(s) E
H2O(l) ? H2O(s) 6.01kJ
C12H22O11 NaClO3 H2SO4? C CO2 H2O NaCl
E
4
Ex a) Silver melts (?E 8.7 kJ/mol)

• 8.7kJ Ag(s) ? Ag(l)

5
Ex b) CO2 condenses (?E -23 kJ/mol)

• CO2(g) ? CO2(l) 23kJ

6
Ex c) NaCl dissolves (?E 15 kJ/mol)

• 15kJ NaCl(s) ? NaCl( )

aq