EXPERIMENT 11

1. EXPERIMENT 11 TYPES OF CHEMICAL REACTIONS

2. Concepts: Majority of the chemical reactions encountered in the laboratory and those that occur in our environment fall into one of the following types: 1. Combination (synthesis) – It is the reaction in which 2 or more substances combine to form a single product. The reactants may be elements or compounds, but the product is always a single compound.

3. 2. Decomposition – It is the reaction in which a single substance, usually a compound, breaks down into 2 or more substances which may be elements or simpler compounds. There is only a single reactant in a decomposition reaction. 3. Single Replacement or Displacement or Substitution – It is the reaction in which one element reacts by taking the place of another element in a compound. This type of reaction

4. always has 2 reactants. To determine which element will be displaced or substituted, reference may be made to the electromotive or activity series or the observed chemical reactivities of elements according to their arrangement in the periodic table. 4. Double Replacement or Double Decomposition or Exchange Reaction – It is the reaction in which the positive ion from one compound takes the negative ion of another compound,

5. and the remaining ions also combine to form another ionic compound. In this reaction, 2 ionic compounds serve as reactants. What happens during chemical reactions are represented by chemical formulas and notations (+, -, and signs) set up as symbolic sentences known as chemical equations. A chemical equation is not considered valid until it is balanced.

8. Objectives: • To distinguish among the different types of chemical reactions. • To identify the reactants and products of chemical reactions. • To develop skill in writing and balancing equations.

9. Materials and Equipments: • Blue and red litmus paper • Bottle with cover • Clay triangle • Crucible tong • Crucible with cover • Evaporating dish • Graduated cylinder • Nail, 1inch

10. Softdrink straw • Spatula • Stirring rod • Test tube holder • Test tubes • Tirril burner • Triple beam balance • Tripod • Watch glass

11. Reagents: • Starch solution • Chlorine water • Distilled water • Phenolphthalein • 0.01 M NaOH • 0.1 M KI • 0.1 M AgNO3 • 0.1 M FeCl3

12. 0.1 M KSCN • 0.1 M NaCl • 0.5 M CuSO4 • 6.0 M HCl • (NH4) 2CO3 • BaCl2 2H2O • CoCl2 H2O

13. Results:

16. Questions: 1. What compound in your breath reacted with the solution in A-2 that caused the change in its color? Answer: The compound that reacted with the solution was the carbon dioxide.

17. 2. What is the substance formed in the nail in C-1? From this result, which is more active iron or copper? Answer: The substance formed was the rust(ferrous sulfate). The more active element was the iron. 3. What substance produced in the reaction between chlorine water and Kl was confirmed by its reaction with starch? Answer: The substance produced was Iodine because the starch turned bluish black.

18. 4. What is the chemical composition of the precipitate formed when the sodium chlorine solution was mixed with silver nitrate solution? Answer: A white precipitate was formed after the mixture of NaCl and AgNO₃.

19. Submitted by: GROUP VII • Papillero, Micah • Patricio, Deseree • Paulo, Lea Carla • Pitahin, Lynette • Remorosa, Claudia Helena

20. GROUP VIII • Roldan, Katherine • Salonga, EmirenzCharmiane • Santos, Jasmine • Singh, Queencel Joyce • Villanueva, Jengale