# decomposition reactions

## other examples of decomposition reactions

Two more examples of decomposition reactions are described below. Carbonic acid (H2 CO3 ) is an ingredient in soft drinks. A decomposition reaction takes place when carbonic acid breaks down to produce water (H2 O) and carbon dioxide (CO2 ). This occurs when you open a can of soft drink and some of the carbon dioxide fizzes out. The equation for this reaction is: H2 CO3 H2 O + CO2 Another decomposition reaction occurs when water (H2 O) breaks down to produce hydrogen (H2 ) and oxygen (O2 ) gases (see Figure 1.1). This happens when an electric current passes through the water, as illustrated below. The equation for this reaction is: 2 H2 O 2 H2 + O2 Decomposition of water. Q: What ratio of hydrogen molecules (H2 ) to oxygen molecules (O2 ) is produced in the decomposition of water? A: Two hydrogen molecules per oxygen molecule are produced because water (H2 O) has a ratio of two hydrogen atoms to one oxygen atom.

## what is a decomposition reaction

A decomposition reaction occurs when one reactant breaks down into two or more products. It can be represented by the general equation: AB A + B In this equation, AB represents the reactant that begins the reaction, and A and B represent the products of the reaction. The arrow shows the direction in which the reaction occurs. Q: What is the chemical equation for the decomposition of hydrogen peroxide (H2 O2 ) to water (H2 O) and oxygen (O2 )? A: The equation for this decomposition reaction is: 2 H2 O2 2 H2 O + O2

## instructional diagrams

No diagram descriptions associated with this lesson

## questions

which general equation represents a decomposition reaction?

``````a) a + b  ab

-->  b) ab  a + b

c) ab + c  ac + b

d) ac  a + b
``````

products of decomposition reactions are always individual elements.

``````a. true

-->  b. false
``````

examples of decomposition reactions include

``````a) 2h2o2  2h2o + o2.

b) nh3 + h2o  nh4oh.

c) 2nacl  2na + cl2.

-->  d) two of the above
``````

the reaction 2al2o3 4al + 3o2 is a decomposition reaction.

``````-->  a. true

b. false
``````

## diagram questions

No diagram questions associated with this lesson