Heat of Reaction (4)

Formation of insoluble salts

Insoluble salts are formed by a double decomposition reaction that involves heat change, which is known as heat of precipitation

The thermochemical equation for the formation of barium sulphate, BaSO4 precipitate

The heat of precipitation of barium sulphate, BaSO4

Is -42 kJ mol−1

White precipitate of barium sulphate, BaSO4

Steps to calculate the heat of precipitation of lead(II) sulphate, PbSO4

Step 1: Calculate the number of moles of lead(II) sulphate, PbSO4 precipitate formed

Steps to calculate the heat of precipitation of lead(II) sulphate, PbSO4

Step 2: Calculate the heat change

Steps to calculate the heat of precipitation of lead(II) sulphate, PbSO4

Step 3 : Calculate the heat change for the formation of 1 mole of precipitate

Steps to calculate the heat of precipitation of lead(II) sulphate, PbSO4

Step 4: Write the heat of reaction, ∆H

Definition of heat of displacement

Is the heat change when one mole of a metal is displaced from its salt solution by a more electropositive metal

Steps to calculate the heat of displacement of iron, Fe from its salt solution

Step 1: Write the chemical equation