This document defines acids, bases, and salts according to three theories: 1) Arrhenius defines acids as substances that yield hydrogen ions in water and bases as substances that yield hydroxide ions in water. Neutralization produces salt and water. 2) Bronsted-Lowry defines acids as proton donors and bases as proton acceptors. Neutralization involves the transfer of a proton from an acid to a base. 3) Lewis defines acids as electron pair acceptors and bases as electron pair donors. Neutralization involves the sharing of an electron pair between an acid and base.

1. Acids, Bases and
Salt
John Rey D. Ravago
BSED SCIENCE 1-A

2. Facts About Acids
 Have sour taste;
 Turn blue litmus dye to red;
 Colorless with phenolphthalein (often used as an indicator
in acid–base titrations);
 Corrosive, can dissolve metals; and
 React with metals to liberate hydrogen gas.

3. Facts About Bases
 Have bitter taste;
 Feel slippery or greasy to touch;
 Turn red litmus dye to blue;
 Magenta red color with phenolphthalein; and
 Strong bases liberate NH3 from ammonium salts.

4. DEFINITION OF ACIDS,
BASES, AND SALTS

5. A. The Arrhenius concept is based on the type of ions produced
in aqueous solution.
 Acid is a substance which yields hydrogen ions (H+) or
hydronium ions (H3O+) in aqueous solution.
Example of Arrhenius acids are HCl, NHO3, H2SO4,
HC2H3+O2.
 Base is a substance which yields hydroxide ions (OH-) in
aqueous solution.
Example of Arrhenius bases are KOH, NaOH, Mg(OH)2.

6. • Neutralization refers to the reaction between an acid and a
base. When an Arrhenius acid reacts with an Arrhenius base,
salt and water are produced as shown in the following
equation.
HCl + NaOH → NaCl + H2O
Acid Base Salt Water
• Salt are ionic compounds made up of a negative ion, except OH
and any positive ion, Except H+. Example are KNO3, Na2CO3,
AlPO4 and CaSO4.

7. B. The Bronsted-Lowry concept is based on wherever a
proton, H+ is donated or accepted.
 Acid is a proton donor.
 Bases is a proton acceptor.
• According to the Bronsted-Lowry concept, neutralization
involves the transfer of a proton (H+) from a Bronsted-Lowry
acid to a Bronsted-Lowry base as shown in the following
equation.
HC2H3O2 + HOH → C2H3O2
- + H3O+
Acid1 Base2 Base1 Acid2

8. • Conjugate acids and Bases
Reactioon between a Bronsted-Lowry acid and a
Bronsted_Lowry base result in the formation of another Bronsted-Lowry
acid and base. For each reaction, there are two pairs of acids and bases,
where each pair differ only in the number of H+ or protons. The species
with one proton more is the acid while the species with has one proton
less is the base. Each pair is called conjugate acid-base pair. The
conjugate acid-base pairs in this particular neutralization reaction are:
 HC2H3O2 – C2H3O2
- or ascetic acid – acetate ion
 H3O+ − HOH or hydronium ion – water
• Water is said to be amphiprotic, which means it can act as an acid in
the presence of a strong base, and as a base in the presence of a strong
acid.

9. C. The Lewis concept is based on the shared electron pair.
 Acid is an electron pair acceptor.
 Base is an electron pair donor.
Example of Lewis acids are Ag+, BF3, AlCl3 while NH3
(ammonia) and RNH2 (amines) are classified as Lewis bases.
: NH3 + HCl → [H: NH3]+ Cl-
Base Acid Salt

10. Summary of definitions of acids and bases
Theory Acid Base
Arrhenius Release H+ in aqueous
solution
Release OH+ in
aqueous solution
Bronsted-Lowry Proton donor Proton acceptor
Lewis Electron pair acceptor Electron pair donor

11. Mag Review !!!