Answer to Question #124543 in Organic Chemistry for Nyarko Benjamin

Question

Explain how you would use the Arrhenius concept to explain the basicity of Na2CO3 and acidity of AlCl3.

Answer 1

Even though both compounds do not contain H⁺ and OH^- ions, Arrhenius concept in these cases can be applied from the point that adding Na₂CO₃ to water increases the concentration of OH^- ions, and AlCl₃ increases the concentration of H⁺.

For Na₂CO₃:

CO₃^2- + H₂O <-> HCO₃^- + OH^- => the solution is basic.

AlCl₃ partially hydrolyzes forming HCl:

AlCl₃ + 3H₂O <-> Al(OH)₃ + 3HCl.

HCl as a strong acid, in its turn, dissociates forming H⁺ ions:

HCl --> H⁺ + Cl^- => the solution is acidic.