This document outlines the key steps and equations for calculating heat changes during various types of chemical reactions, including heat of precipitation, displacement, neutralization, and combustion. The steps include writing the chemical and ionic equations, calculating the moles of reactants and products, measuring the heat change using temperature changes, and dividing the heat change by moles to determine the molar enthalpy change. Energy diagrams are also used to illustrate whether reactions are exothermic or endothermic.

1. Heat of precipitation, ∆H Heat of displacement,, ∆H Heat of neutralisation, ∆H Heat of combustion, ∆H
Example of
set – up of apparatus
1. Chemical equation Reactans A + Reactans B → Products C + Products D
2. Ionic equation Depends on reactants during reaction H+
+ OH-
→ H2O
3. No. moles, x
=mv/1000
X = molarity x volume [ use any one] X= molarity solution x volume solution X for H+
= molarity acid x volume acid
X for OH-
= molarity alkali x volume alkali X =
molarmass
gmassbeforegmass )()( 
4. Heat changes,H
=mc∆Ө
H= mass of mixture x c x [T2-T1] H= mass of solution x c x [T2-T1] H= mass of mixture x c x [T2-T1] H= mass of water x c x [T2-T1]
5. ∆H= H/x ∆H= Heat changes /no. mole
6. Energy level
diagram
A + B
C + D
∆H = - kJ mol-1
Energy
Exothermic Reaction
0.5 g zinc
25cm3
CuSO4
0.2 mol dm-3
A + B
C + D
∆H = + kJ mol-1
Endothermic Reaction