How do we represent the reaction of hydrochloric acid with stoichiometric calcium carbonate? Do we need to consider oxidation states?

1 Answer
May 27, 2017

This is an acid-base reaction, in which no redox transfer occurs........

Explanation:

We can write out the stoichiometric equation:

#CaCO_3(s) + 2HCl(aq) rarr CaCl_2(aq) + CO_2(g) +H_2O(l)#

And the net ionic equation:

#CO_3^(2-) + 2H_3O^(+) rarr CO_2(g)uarr +3H_2O(l)#

And we can include oxidation numbers on reactants and products:

#stackrel(+IV)CO_3^(2-) + 2H_3O^(+) rarr stackrel(+IV)CO_2(g)uarr +3H_2O(l)#

Are these equations balanced with respect to mass and charge? They need to be if we purport to represent chemical reality!

The oxidation numbers of hydrogen and carbon remain at #stackrel(-II)O# and #stackrel(+I)H# respectively.