The document defines acids and bases according to three theories: 1) Arrhenius theory defines acids as substances that produce H+ ions in water and bases as substances that produce OH- ions in water. 2) Bronsted-Lowry theory defines acids as proton donors and bases as proton acceptors in any solvent. 3) Lewis theory uses electron pair donors and acceptors to define acids and bases and applies to a wider range of substances. The document also discusses pH scales, strong vs. weak acids and bases, and factors that contribute to acid rain in certain regions.

1. By : Siti Auliaddina

2. Do you know the definition of acids
and bases in general ?

3. Produce H+ (as H3O+) ions in water
Produce a negative ion (-) too
Taste sour
Corrode metals
React with bases to form salts and water

4.  Produce OH- ions in water
 Are electrolytes
 Feel soapy, slippery
 React with acids to form salts and water
LecturePLUS Timberlake 4

6. • Used for acid and bases in solution
(neutralization)
• Cations (positive ions) derived from the
bases and anions (negative ions) derived
from acid
• Salt: compounds which can remove ion of
• H + positive and negative ion of non OH-

7.  Acids produce H+ in aqueous solutions
water
HCl H+(aq) + Cl- (aq)
 Bases produce OH- in aqueous solutions
water
NaOH Na+(aq) + OH- (aq)

8. • In this idea, the ionization of an acid by water is
just one example of an acid-base reaction.
H H
+
Cl H + O HO + Cl
H H
acid base conjugate acid conjugate base
conjugate acid-base pairs
• Acids and bases are identified based on whether
they donate or accept H+.
• “Conjugate” acids and bases are found on the
products side of the equation. A conjugate base
is the same as the starting acid minus H+.

9. Arrehenius  Acids – produce H+
only in water  Bases - produce OH-
 Acids – donate H+
Bronsted-Lowry
 Bases – accept H+
any solvent
Lewis  Acids – accept e- pair
used in organic chemistry,  Bases – donate e- pair
wider range of substances

10. Acid, Base Name
or Salt
CaCl2 ______ _________________
KOH ______ _________________
Ba(OH)2 ______ _________________
HBr ______ _________________
H2SO4 ______ __________________

11.  The pH scale
measures
how acidic
or basic a
solution is.

12.  The pH scale is the concentration of
hydrogen ions in a given substance.
pH log H

13.  Acids have a ph from 0-7
 Lower pH value indicates a
stronger acid.
 Bases have a pH from 7-14
 Higher pH value indicates a
stronger base.

14. Strong acids/bases – 100% dissociation into ions
HCl NaOH
HNO3 KOH
H2SO4
Weak acids/bases – partial dissociation,
both ions and molecules
CH3COOH NH3
Weak Acid Weak Base

15. pH of Rainwater
across United States in 2001
You
are
here!
Why is the eastern US more acidic?
http://nadp.sws.uiuc.edu/isopleths

16. Dissolved carbon dioxide lowers the pH
CO2 (g) + H2O  H2CO3  H+ + HCO3-
Atmospheric pollutants from combustion
NO, NO2 + H2O …  HNO3 both
strong
acids
SO2, SO3 + H2O …  H2SO4
pH < 5.3