Types of Chemical Reactions

The chemical reaction: 2 H₂O → 2 H₂ + O₂ is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

You can recognize a decomposition by noticing a compound or molecule breaks into smaller chemical species. 

The chemical reaction: 8 Fe + S₈ → 8 FeS is a

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

A synthesis reaction or direct combination is the reverse of a decomposition reaction. In a synthesis reaction, two or more reactants combine to form a more complex molecule.

The chemical reaction: AgNO₃ + NaCl → AgCl + NaNO₃ is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

A double displacement reaction is sometimes called a metathesis reaction. In this type of chemical reaction, two reactants exchange ions to form two different compounds.

The chemical reaction: Zn + H₂SO₄ → ZnSO₄ + H₂ is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

A single displacement reaction is also called a substitution reaction. It's a common type of reaction in which one element is displaced by another. It takes the form: A + BC → AC + B

The chemical reaction: 2 H₂ + O₂ → 2 H₂O is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

The formation of water from its elements is a type of synthesis reaction. Some people also consider it a combustion reaction because oxygen is used and energy is released. However, no carbon dioxide is released.

The chemical reaction: CH₄ + 2 O₂ → CO₂ + 2 H₂O is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

This reaction meets all of the criteria for classification as a combustion reaction. Here, a fuel and an oxidizer react to produce water and carbon dioxide. Heat is also released by this reaction.

The chemical reaction: 2 Fe + 6 NaBr → 2 FeBr₃ + 6 Na is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

This is another example of a single displacement reaction, since iron and sodium displace each other in the reaction.

The chemical reaction: Pb + O₂ → PbO₂ is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

This is a basic example of a synthesis reaction where two distinct things are coming together.

The chemical reaction: 2 CO + O₂ → 2 CO₂ is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

This is a synthesis reaction.

The chemical reaction: Ca(OH)₂ + H₂SO₄ → CaSO₄ + 2 H₂O is a:

• Synthesis Reaction

• Decomposition Reaction

• Single Displacement

• Double Displacement

• Combustion

Answer explanation

This is a double displacement reaction. The hydroxide and sulfate anions switch cations.