CHEMICAL REACTIONggggggggggggggddss.pptx

chemical reaction

1. Chemical Reaction

2. Apply the principles of conservation of mass to chemical reactions; Participate in class activity and class discussion, and Take and pass the mastery level of 75% OBJECTIVES

3. Substances undergo chemical bonding in order that atoms can become more stable. Chemical bonding results to breaking of bonds and formation of new bonds, thus new substances are formed. Formation of new substances means a chemical reaction has taken place.

4. When a physical change occurs, there is no breaking and forming of bonds. There are certain things that will help you determine if a chemical reaction has taken place. You call these evidences of chemical reactions. These are: production of light, evolution of gas, change in temperature, change in intrinsic properties (color, odor), and formation of precipitate.

5. In a chemical reaction there are reactants and products. The substances that undergo reaction are called reactants and the substances produced at the end of the reaction are called products.

6. Activity 1: What’s in a Reaction Example: Word equation: Sodium reacts with chlorine to form Sodium chloride Chemical Formula: Na + Cl NaCl Reactant/s Product Na and Cl NaCl

7. Directions: Listed below (A) are examples of chemical reactions. Determine the reactants and the products in every reaction. 2. Copy and fill in Table 1 with the reactants and products from the chemical reactions in A 3. Below each number on the table, write the symbol or formula of the reactant and products. Number 1 is given as an example. Chemical Reactions Iron reacts with copper sulphate (CuSO4) and forms iron (II) sulphate (FeSO4) and copper 2. Magnesium combines with oxygen gas (O2) to produce magnesium oxide 3. Hydrogen peroxide (H2O2) in the presence of manganese dioxide (MnO2) produces water and oxygen gas. 4. Acetic acid (CH3COOH) and sodium bicarbonate (NaHCO3) produce sodium acetate with the release of carbon dioxide (CO2) gas and water. 5. Copper sulphate (CuSO4) reacts with sodium hydroxide (NaOH) to produce insoluble copper (II) hydroxide Cu (OH)2 and sodium sulphate (Na2SO4) solution.

8. Table 1. Reactants and Products Reaction Reactants Products Iron, Copper sulfate Iron (II) sulphate, Copper Fe, CuSO4 FeSO4, Cu

9. Activity 2: WHAT’S MY SYMBOL Directions: Using the symbols and formulas in Activity 1, write the chemical reaction using the symbols to complete chemical equation. Table 2. Chemical equation Reaction Chemical Equation 1 Fe + CuSO4 FeSO4 + Cu 2 3 4 5

10. A chemical equation is a chemist’s shorthand for a chemical reaction. The equation distinguishes between the reactants, which are the starting materials and the products which are the resulting substance/s. It shows the symbols or formulas of these substances, and the ratio of the substances as they react.

11. REACTANT PRODUCT Magnesium + Oxygen Magnesium Oxide Mg + O2 MgO H + O2 H2O

12. According to Antoine Lavoisier's 1789 discovery a chemical reaction must conform to the Law of Conservation of Mass which states that mass is neither created nor destroyed in chemical reactions. In some other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction.

13. Example: Na + Cl NaCl Word equation: Sodium reacts with chlorine to form sodium chloride. Atomic no: Cl=35, Na=23 No. atoms X atomic number of each element 1 (23) g + 1 (35) g = 1(23)g + 1 (35) g 23g + 35 g =23 g+ 35 g 58 g = 58 g Therefore: Reactant= Product = 58 g The chemical equation must also balance in order to follow the Law of Conservation of Mass. But before that, we must know first the symbol used in a chemical equation, know how to distinguished between reactant and product in a chemical reaction and the different types of chemical reaction.

14. Symbols used in Chemical Equation There are other symbols used in writing a chemical equation:

15. A chemical equation is a chemist’s shorthand for a chemical reaction. The equation distinguishes between the reactants, which are the starting materials and the products which are the resulting substances/s. It shows the symbols or formulas of the reactants and products, the phases (solid, liquid, gas) of these substances, and the ratio of the substances as they react.

16. ACTIVITY 3: WE SIMPLY CLICK TOGETHER Directions. Refer to Activity 1 What’s in a Reaction?” and answer the following. Guide Questions: In the second chemical reaction, how many reactants are used? How many product/s is/are formed? ___________________________________________________ 2. In the third chemical reaction, how many reactants are used? How many product/s is/are formed? ___________________________________________________ 3. In the first chemical reaction, what changes did copper and iron undergo during the reaction? What can you conclude about iron? ____________________________________________________________ 4. In the fourth chemical reactions, how many reactants and products are involved? What kind of substance are they? __________________________________________________________ 5. In the fifth chemical reaction, both the reactants and products are compounds made of positive and negative ions, what did you notice with the pairing of positive and negative ions in the reactant and product side? ___________________________________________________________

17. Activity 4. Types of Chemical Reactions Directions. Using your answers in Activity 2. – What’s MY Symbol- determine the type of reaction in each item. Copy and complete the table in your answer sheet. Table 3. Types of Chemical Reactions REACTION CHEMICAL EQUATION TYPE OF CHEMICAL REACTION 1 Fe + CuSO4 FeSO4 + Cu SINGLE DISPLACEMENT 2 3 4 5

18. Activity 4: Balancing Act Procedure: 1. Analyze the information that can be gathered in the chemical equation: 2H2 + O2 2H2O 2 molecules of H2 + 1 molecule of O2 2 molecules of H2O 2 moles of H2 + 1 mole of O2 2 moles of H2O 4 atoms of H + 2 atoms of O 4 atoms of H and 2 atoms of O

19. Note that the coefficient (number) placed before the formulas indicate the number of molecules or moles. Determining the correct coefficients balances the number of atoms in the reactant and the in the product side, allowing it to follow the Law of conservation of mass

20. Directions. Copy and complete the table in your answer sheet. Balance the chemical

21. Have you observed simple chemical reactions in your daily chores at home? Identify common chemical reactions in your home and explain how these reactions happen. ___________________________________________________________________. ESSAY