# What are 3 examples of a chemical change?

Oct 31, 2016

$i .$ $\text{ Fixation of carbon dioxide by photosynthesis}$
$i i .$ $\text{Combustion of hydrocarbons}$
$i i i .$ $\text{Fixation of dinitrogen to give ammonia}$

#### Explanation:

The three examples are probably the 3 most important chemical reactions. Simple sugars are produced from carbon dioxide and water using sunlight as the energy source:

$6 C {O}_{2} + 6 {H}_{2} O + \Delta \left(\text{sunlight}\right) \rightarrow {C}_{6} {H}_{12} {O}_{6} + 6 {O}_{2}$

${C}_{6} {H}_{14} + \frac{19}{2} {O}_{2} \rightarrow 6 C {O}_{2} + 7 {H}_{2} O + \Delta$

And combustion allows reclamation and use of the energy stored in the photosynthesis reaction (this is the reverse of the photosynthesis reaction).

And the Haber process allows fixation of dinitrogen to give ammonia:

${N}_{2} + 3 {H}_{2} \rightarrow 2 N {H}_{3}$