This document discusses acids and bases according to several theories:
- According to the Arrhenius theory, acids donate H+ ions and bases donate OH- ions in water. This theory does not explain behavior in non-aqueous solutions.
- The Bronsted-Lowry theory states that acids are proton donors and bases are proton acceptors. Conjugate acids and bases are formed in acid-base reactions.
- The Lewis theory defines acids as electron pair acceptors and bases as electron pair donors. Covalent bonds are formed between them.
- Strong acids and bases fully dissociate in water while weak acids and bases only partially dissociate. Examples of strong and weak acids and bases are provided
2. ACID
● Produce H+ ions in water
● Have a sour taste
● Breakdown metals
● Formula starts with H
● Poisonous and corrosive to skin
● PH less than 7
3. ACID
● Turns blue litmus to red
● Dissolve in water to form solution which conduct electricity
● React with reactive metals to form salt and hydrogen
● Acid reacts with carbonates and hydrogen carbonates to
form a salt,water and carbon dioxide
● Acid reacts with metal oxides and hydroxides to form a salt
and water
4. BASE
● Produce OH- ions in water
● Have a bitter taste and slippery feel
● Break down fats and oils
● Formula ends with OH
● Poisonous and corrosive to skin
● PH greater than 7
5. BASE
● Turn red litmus blue
● React with acids to form salt and water
● Heated with ammonium salts gives off ammonia
gas
● React with a solution of one metal salt to give
another metal salt and metal hydroxide
7. Arrhenius Concept Of Acids and Bases
● According to the Arrhenius concept of acids and
bases,an acid is a substance that,when dissolved in
water,increases the concentration of hydronium
ion(H3
O+)
● It releases H+ ion in water
● The aqueous hydrogen ion is actually,chemically
bonded to water that is ,H3
O+
8. Arrhenius Concept Of Acids and Bases
● A base,in the Arrhenius concept,is a substance
that,when dissolved in water,increases the
concentration of hydroxide ion,OH-(aq)
● It releases OH- ion in water
9. Limitations Of Arrhenius Theory
● This theory does not explains the acidic
and basic behaviour of substance in
non-aqueous solvent
10. Bronsted-Lowry Acid and Bases
● Bronsted-Lowry acid can donate a proton
● Bronsted-Lowry base can accept a proton
● Must contain a non-bonding pairs of electrons
● Conjugate base of an acid is the species
remaining after the acid has lost a proton
11. Bronsted-Lowry Acids and Bases
● Conjugate acid is the species formed after the base has
accepted a proton
● HCl + H2
O ⟷ H3
O+
+ Cl-
● Water is conjugate base of H3
O+
and Cl-
is conjugate base of
HCl-
● Water can act as both Acid and base.Hence known as
Amphiprotic
● Strong acids have weak conjugate base
● Weak acids have strong conjugate base
12. Lewis Acids and Bases
● Bases can donate a pair of electrons
● Acids can accept a pair of electrons
● Covalent bond is formed
● Many Lewis Acid don’t contain hydrogen
13. Strong Acids and Bases
● Strong acid and base is completely dissociated into its ions in aqueous
solutions
● Strong acids have a PH of 0 to 3
● Strong base have a PH of 11 to 14
● Strong acids:
● HCl(Hydrochloric acid)
● HNO3
(Nitric acid)
● H2
SO4
(Sulfuric acid)
● Strong bases:
● NaOH(Sodium Hydroxide)
● KOH (Potassium Hydroxide)
● Ba(OH) (Barium Hydroxide)
14. Weak Acids and Bases
● Weak acids and bases is slightly dissociated into their ions in
aqueous solution
● Weak Acids:
● CH3
COOH (Ethanoic acid)
● H2
CO3
(Carbonic acid)
● Weak Bases:
● NH3
(Ammonia)
● C2
H5
NH2
(Amino ethane)