Reactions Types

Double replacement reactions, also known as metathesis reactions, are chemical reactions in which the cations and anions of two ionic compounds exchange places to form two new ionic compounds. The general equation for a double replacement reaction is:

$$ AB + CD → AD + CB $$
where A and C are cations and B and D are anions.

Conditions for Double Replacement Reactions Types

Double replacement reactions occur when:

• One of the reactants is a strong acid or base.
• Both reactants are soluble in water.
• The products are insoluble in water (precipitation reaction).
• The products are gases.

Types of Double Replacement Reactions Types

There are three main types of double replacement reactions:

• Precipitation reactions: These reactions produce an insoluble solid precipitate.
• Gas-evolution reactions: These reactions produce a gas as one of the products.

• Acid-base reactions: These reactions produce water and a salt. VVVV

Neutralization

$$ Acid+Base → H_2O + Salt $$

• Acid and Base will neutralize each other to a pH of 7, if perfectly balanced
• Used in Titration to find the molarity of one of the reactants

Example of a Double Replacement Reaction

The reaction between sodium chloride ( $ NaCl $ ) and silver nitrate ( $ AgNO_3 $ ) is a double replacement reaction that produces a precipitate of silver chloride ( $ AgCl $ ):

$$ NaCl_{{(aq)}} + AgNO{3_{(aq)}} → AgCl_{{(s)}} + NaNO{3_{(aq)}} $$