2.7 Acid reactions

2.7 Acid reactions

Acid redox reactions

As you can see from the image, when you add a piece of metal to an acid, bubbles of gas are given off

Acid reactions

There are two different type of reactions when acids react in redox reactions.

With hydrochloric acid (HCl) and sulfuric acid (H₂SO₄) the species that is reacting is the H⁺ ion.

With nitric acid (HNO₃) it is the NO₃^- that is reacting.

E.g. Hydrochloric acid and calcium metal

2H⁺_(aq)           +      2e^-          --> H_2(g)

 

Ca _(s)            --> Ca²⁺ _(aq)          -     2 e^-

 

Ca _(s)   +          2H⁺ _(aq)           -->    H_2(g)   +  Ca²⁺_(aq)  

E.g. Nitric acid and copper metal

NO₃^- _(aq)  + 2H⁺     +      1e^-      --> NO_2(g)    + H₂O

 

 Cu_(s)          --> Cu²⁺_{(aq)    +}    2 e^-  

2NO₃^- _(aq)  + 4H⁺     +      2e^-      --> 2NO_2(g)    +2 H₂O

 

 Cu_(s)          --> Cu²⁺_(aq)   +     2 e^-  

 

2NO₃^-_(aq)   + Cu   + 4H⁺  --> 2H₂O   +  Cu²⁺  + 2NO_2(g)