Evergy & Percent Yield

-Enthalpy is the energy stored in chemical bonds
-Symbol of Enthalpy is H
      - units of joules (J)
- Change in Enthalpy is ΔH
- In exothermic rxns enthalpy decreases
-In endothermic rxns enthalpy increases

Calorimetry
- To experimentally determine the heat released we need to know 3 things
   1) temperature change ( ΔT)
   2) Mass (m)
   3) specific Heat capacity (c)
There are related by the equation: ΔH = mC ΔT

ex: calculate the heat required to warm a cup of 400g of water (C= 4.18J/g °C) from 20.0 °C to 50.0 °C.
 ΔH=mCΔT
 ΔH= (400)(4.18)(50.0-20.0)
 ΔH=50160 J = 50.2 kJ


-Paul Dinh