DOUBLE DISPLACEMENT REACTION:
You will observe that a white substance, which is insoluble in water, is formed. This insoluble substance formed is known as a precipitate. Any reaction that produces a precipitate can be called a precipitation reaction.
Na2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq)
The white precipitate of BaSO4 is formed by the reaction of SO42- and Ba2+. The other product formed is sodium chloride which remains in the solution. Such reactions in which there is an exchange of ions between the reactants are called double displacement reactions.
A precipitation reaction refers to the formation of an insoluble salt when two solutions containing soluble salts are combined. The insoluble salt that falls out of solution is known as the precipitate, hence the reaction's name. Precipitation reactions
AgNO3 + NaCl → AgCl + NaNO3
The precipitate forms because the solid (AgCl) is insoluble in water. That is true for all precipitates, the solids are insoluble in aqueous solutions.
Shaalaa.com | Types of reaction - Double Displacement reaction
When the substance ‘A’ is added to a solution of BaSO4, a yellow precipitate is formed.
- What do you think substance A is likely to be?
- Name the precipitate.
- Which type of reaction is this?