4/8 Notes – Acid/Base Theories

 

  1. Acids and Bases

            A.        Your knowledge

            B.        Arrhenius Theory

                        1.         Acid

                                    a.         Definition – breaks up in solution to form hydrogen ions

                                    b.         Example

                                                HCl à H+ + Cl-

                                                *Remember that aqueous solutions break up to form ions in solution

                        2.         Base

                                    a.         Definition – breaks up in solution to form hydroxide ions

                                    b.         Example

                                                NaOH à Na+ + OH-

3.                  Electrolyte – charged particles in solution that conduct electricity

C.        Bronsted-Lowry Theory

                        1.         Acid

                                    a.         Def – donates a proton in solution to form the hydronium ion

                                    b.         Example

                                                HCl + H2O à H3O+ + Cl-

                                                Note that HCl donated H (proton) to form H3O+

                        2.         Base

                                    a.         Def – accepts a proton in solution

                                    b.         Example

                                                HCl + H2O à H3O+ + Cl-

                                                Note that H2O accepted the H

3.                  Hydronium ion – water with a hydrogen ion attached

4.         Acid/Base Reactions

                                    a.         Conjugate base – former acid that donated the proton (product side)

                                    b.         Conjugate acid – former base that accepted the proton (product side)

                                    c.         Examples

l      Identify the acid, base, conjugate acid, and conjugate base in the following reaction.

HNO3 +           NaOH à        HOH +            NaNO3

            Acid                Base                Conj Acid       Conj Base

l      What is the conjugate base of the following? (Just remove an H)

            H2SO3 à HSO3-

            HF à F‑

D.        Naming Acids

                        1.         Binary acids

                                    a.         Def – acid with two elements, one of them being hydrogen

                                    b.         How to name?                                                                         HCl

                                                1.         Use the prefix hydro                                                   hydro

                                                2.         Add the root of the second element’s name               hydrochlor

                                                3.         Add the suffix –ic acid                                               hydrochloric acid

                        2.         Ternary Acids

                                    a.         Def – acid with three elements, one of them being hydrogen and usually oxygen

                                    b.         How to name?

                                                1.         -ate à -ic acid

                                                            -ite à ous acid

2.         If the polyatomic ion name is not known, look at the family it is in and name it from the polyatomic ion in its family.

                                    c.         Examples

                                                1.         H2SO4

                                                            SO4  is sulfate à sulfuric acid (note- hydrogen is not mentioned, and it is understood)

2.                  H3AsO4

We have not heard of AsO4, but we know that PO4 is phosphate so AsO4 is arsenate so the name of this acid is arsenic acid.