1. Lecture 5

2. Md Kausher ahmed Instructor Electrical department

3. Chemistry 5913

4. Previous lesson Chemical reaction

5. Lesson declared Explanation of Various kinds of chemical reaction.

6. Learning outcomes After finished this lesson student will able to (1)Define combination reaction and give example. (2)Define decomposition reaction. (3)Define Substitution reaction and example. (4)Define double displacement reaction.

7. Combination reaction Two or more reactants unite to form a single product. S + O 2 ---------> SO 2 sulphur oxygen sulphur dioxide 2 S + 3 O 2 ---------> 2 SO 3 a sulphur oxygen sulphur trioxide 2 Fe + O 2 ---------> 2 FeO iron oxygen iron (II) oxide

8. Decomposition Reactions A single reactant is decomposed or broken down into two or more products. CaCO 3 ----------> CaO + CO 2 calcium carbonate calcium oxide carbon dioxide 2 H 2 O -----------> 2 H 2 + O 2 water hydrogen oxygen 2 KClO 3 -----------> 2 KCl + 3 O 2 potassium chlorate potassium chloride oxygen

9. Substitution or Single Replacement Reactions A single free element replaces or is substituted for one of the elements in a compound. The free element is more reactive than the one its replaces.

10. Zn + 2 HCl ----------> H 2 + ZnCl 2 zinc hydrochloric acid hydrogen zinc chloride Cu + 2 AgNO 3 -----------> 2 Ag + Cu(NO 3 ) 2 copper silver nitrate silver copper (II) nitrate H 2 + 2 AgNO 3 -----------> 2 Ag + 2 HNO 3 hydrogen silver nitrate silver nitric acid 2 Na + 2 H 2 O -----------> 2 NaOH + H 2 sodium water sodium hydroxide hydrogen

11. Metathesis or Double Displacement Reactions This reaction type can be viewed as an "exchange of partners." For ionic compounds, the positive ion in the first compound combines with the negative ion in the second compound, and the positive ion in the second compound combines with the negative ion in the first compound.

12. HCl + NaOH -----------> NaCl + HOH hydrochloric sodium sodium water acid hydroxide chlo ride BaCl 2 + 2 AgNO 3 ----------> 2 AgCl + Ba(NO 3 ) 2 barium silver silver barium chloride nitrate chloride nitrate (pr ecipitate) CaCO 3 + 2 HCl -----------> CaCl 2 + H 2 CO 3 calcium hydrochloric calcium carbonic carbonate acid chloride acid

13. Feedback (1)Explain combination reaction. (2) Explain decomposition reaction. (3)Explain substitution reaction. (4)Explain double displacement reaction.

14. Thanks to all