# What takes place in a chemical reaction?

Jul 21, 2017

$\text{What occurs in a chemical reaction?}$

$\text{The formation of new substances.....}$

#### Explanation:

$\text{The formation of new substances.....}$
$\text{...and the making and breaking of strong chemical bonds.}$

Note that this is distinct from physical change......which are largely changes of state......

${H}_{2} O \left(s\right) \stackrel{\Delta}{\rightarrow} {H}_{2} O \left(l\right) \stackrel{\Delta}{\rightarrow} {H}_{2} O \left(g\right)$

or $C {O}_{2} \left(s\right) \rightarrow C {O}_{2} \left(g\right)$

......chemical bonds have not been broken here.......

On the other hand for.........

$C {H}_{4} \left(g\right) + 2 {O}_{2} \left(g\right) \rightarrow C {O}_{2} \left(g\right) + 2 {H}_{2} O \left(l\right)$

or.......

$C a \left(s\right) + C {l}_{2} \left(g\right) \rightarrow C a C {l}_{2} \left(s\right)$

or even......

$N a C l \left(s\right) \stackrel{{H}_{2} O}{\rightarrow} N {a}^{+} \left(a q\right) + C {l}^{-} \left(a q\right)$

....new substances have been formed and strong chemical bonds have been broken, and thus these ARE ALL examples of chemical change.