Ionic Equilibria | Bronsted Lowry Acid Base Theory | Chemistry Class 12 | By Mrs.Shubhada Walawalkar
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This video discuss about bronsted lowry concept of acid and base. Conjugate acid base pairs, relative strength of acid base, Advantages & Limitations bronsted lowry concept of acid and base and Examples of Acid base reactions.
Ionic Equilibria | Bronsted Lowry Acid Base Theory | Chemistry Class 12 | By Mrs.Shubhada Walawalkar
- 1. Chemistry Class 12 3. IONIC EQUILIBRIA Part-3 Bronsted Lowry Theory of Acids and Bases 03-08-2020 s.s.walawalkar. 1
- 3. 3.3.2 Bronsted-Lowry theory According to Bronsted-Lowry theory(1923) Acid :- Acid is the substance that donates proton H+ to another substance. Base :- Base is a substance that accept proton H+ from another substance. e.g. HCl + NH3 NH4 + + Cl Acid-1 Base-2 Acid-2 Base-1 03-08-2020 s.s.walawalkar. 3
- 4. HCl + NH3 NH4 + + Cl Acid-1 Base-2 Acid-2 Base-1 HCL and NH4 + are proton donor .Act as acids 03-08-2020 s.s.walawalkar. 4
- 5. HCl + NH3 NH4 + + Cl Acid-1 Base-2 Acid-2 Base-1 Ammonia and chloride ion are proton acceptor. Act as bases. 03-08-2020 s.s.walawalkar. 5
- 6. Arrhenius acids are also Bronsted acids. But Arrhenius bases are not Bronsted bases. 1. HCL(aq)+ H2O(l) H3O+ + Cl- (aq) acid 1 base2 acid 2 base1 2. NH3 (aq) + H2O(l) NH4 +(aq) + OH-(aq) base2 acid 1 acid 2 base1 3. H2O(l) + CO3 2-(aq) HCO3 -(aq) + OH-(aq) acid 1 base2 acid 2 base1 4. NH4 +(aq) + H2O(l) H3O+(aq) + NH3(aq) acid 1 base2 acid 2 base1 03-08-2020 s.s.walawalkar. 6
- 7. Products of the Bronsted Lowery acid base reactions are acids and bases. A pair of an acid and a base differing by proton is said to be a conjugate acid base pair. 03-08-2020 s.s.walawalkar. 7
- 9. The base produced by accepting the proton from an acid is the conjugate base of that acid. 03-08-2020 s.s.walawalkar. 9
- 10. The acid produced when base accepts a proton is called conjugate acid of that base. 03-08-2020 s.s.walawalkar. 10
- 11. 03-08-2020 s.s.walawalkar. 11 Write the conjugate acids for Bronsted Lowery conjugate base Bronsted Lowery base Bronsted Lowery conjugate acid NH2 - H2PO4 - NH3 H3PO4
- 12. 03-08-2020 s.s.walawalkar. 12 Write the conjugate acids for Bronsted Lowery conjugate base Bronsted Lowery acid Bronsted Lowery conjugate base HCN H2O CN- OH-
- 13. 03-08-2020 s.s.walawalkar. 13 Points to be remember Acid= conjugate base + H+ Base + H+ = conjugate acid Each conjugate acid has one extra proton. Each conjugate base has one proton less.
- 14. Strengths of conjugate Acids and Bases The strength of an acid depends upon its tendency to donate proton and strength of base depends upon its tendency to accept proton . Strong acid good proton donor Strong base good proton acceptor. 1. HCL(aq) + H2O(l) H3O+ (aq) + Cl- (aq) Strong acid 1 base2 acid 2 weak base1 2.CH3COOH + H2O(l) CH3COO- (aq) + H3O+ (aq) weak acid 1 strong base 03-08-2020 s.s.walawalkar. 14
- 15. 03-08-2020 s.s.walawalkar. 15 Points to be remember Strong acid has weak conjugate base. Weak acid has strong conjugate base Strong base has weak conjugate acid. Weak base has strong conjugate acid.
- 16. Advantages of Bronsted Lowery concept:- 1)This concept explain basic characters of substances like Na2CO3, NH3 . 2) This concept is not limited to molecules but explain acidic and basic characters of ionic species. 3) It can explain acid base reaction in the non aqueous medium. 03-08-2020 s.s.walawalkar. 16
- 17. Bronsted Lowery concept fails to explain:- 1)Acidic substances which do not have proton e.g ALCl3 , BF3 2)Reaction between acidic oxides and basic oxides. CaO + SO3 CaSO4 03-08-2020 s.s.walawalkar. 17