Chapter 6: Chemical Reactions

Classify chemical reactions.

A synthesis reaction is a reaction in which two or more substances react to produce a single product.

When two elements react, the reaction is always a synthesis reaction.

Two compounds can also react to create one compound in a synthesis reaction.

All synthesis reactions follow this general equation:

A + B AB

A decomposition reaction is one in which a single compound breaks down into two or more elements or new compounds.

Decomposition reactions often require an energy source, such as heat, light, or electricity, to occur.

Decomposition reactions follow this general equation:

AB A + B

In a single-displacement reaction, one element displaces another in a compound.

Usually a metal will replace another metal, or a halogen will replace another halogen in single displacement reactions

Single displacement reactions follow this general equation:

A + BC AC + B

Double displacement reactions occur when ions exchange between two compounds.

Double displacement reactions will always produce either a precipitate, water, or a gas.

A double-displacement reaction follows the general form

AB + CD AD + BC

Classify the following reactions:

Na2O(s) + H2O(l) ⟶ 2 NaOH(aq)

Ba(NO3)2(aq) + K2SO4(aq) ⟶ BaSO4(s) + 2 KNO3(aq)

2 Al(s) + Fe2O3(s) ⟶ Al2O3(s) + 2 Fe(l)

2 H2O2(aq) ⟶ 2 H2O(l) + O2(g)

Solid calcium reacts with chlorine gas to produce solid calcium chloride.

Write a balanced chemical equation for each synthesis reaction:

Ag(s) + Br2(g)

Mg(s) + Cl2(g)

Write a balanced chemical equation for each decomposition reaction:

Al2O3(s)

H2O(l)