What takes place in a chemical reaction?

1 Answer
Jul 21, 2017

#"What occurs in a chemical reaction?"#

#"The formation of new substances....."#

Explanation:

#"The formation of new substances....."#
#"...and the making and breaking of strong chemical bonds."#

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

#H_2O(s)stackrel(Delta)rarrH_2O(l)stackrel(Delta)rarrH_2O(g)#

or #CO_2(s) rarrCO_2(g)#

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

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

#CH_4(g) + 2O_2(g) rarr CO_2(g) + 2H_2O(l)#

or.......

#Ca(s) + Cl_2(g) rarr CaCl_2(s)#

or even......

#NaCl(s) stackrel(H_2O)rarrNa^+(aq)+Cl^(-)(aq)#

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