Five Types of Reactions

Ag₂S  +  Al  →  Al₂S₃  +  Ag

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Answer explanation

The Al is alone ("single"). It trades places with the Ag.

This is Single Replacement!

SO₂  +  O₂  →  SO₃

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Answer explanation

The SO₂ and the O₂ COMBINE to form just one product: SO₃

H₂CO₃ →  CO₂  + H₂O

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Answer explanation

On the left side (before), there is only ONE reactant.

On the right side (after), we can see that the reactant broke apart into multiple products.

This is Decomposition!

CO   +   O₂  →  CO₂

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Cu  +  H₂SO₄  →  H₂ + CuSO₄

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

H₂O₂  →  H₂O   +   O₂

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

NO₂  +  H₂O  +  O₂  →  HNO₃

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

CH₄  +  O₂  →  CO₂ + H₂O

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Answer explanation

In a Combustion reaction, you'll always see O₂ on the reactants (left) side. Fire needs oxygen!

The products of a combustion reaction are ALWAYS carbon dioxide (CO₂) and water (H₂O).

Na₃PO₄  +  Al₂(SO₄)₃  →  Na₂SO₄  +  AlPO₄

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Answer explanation

Notice: There are no "single" elements. Every element is paired with at least one other element.

This is Double Replacement!

Ca  +  HOH  →  H₂ + Ca(OH)₂ 

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion