Experiment 7: A Study of Chemical Changes: Types of Chemical Reaction
Experiment 7: A Study of Chemical Changes: Types of Chemical Reaction
INTRODUCTION Chemical changes are results of chemical reactions. All chemical reactions involve a change in substance and a change in energy. They are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products. There are different types of chemical reaction classified into 4 general types, namely, Synthesis, Decomposition, Single Replacement and Double Replacement.
METHODOLOGY
A. Synthesis: Place an evaporating dish near the burner. Using a test tube holder, examine and hold a magnesium ribbon near the burner flame until it burns. When it stops burning, put what is left on the evaporating dish. In a clean and dry test tube, mix 1g of P2O5 and 5mL distilled water. Mix well and observe. Add a drop of litmus indicator in the test tube and observe the color change.
B. Decomposition: Mount a clean and dry test tube on an iron stand and place 5g of CuCO3. Attach the open end of the balloon on the test tube and heat CuCO3 for about five minutes. Observe the color change and the balloon.
C. Single Replacement: Stand a clean and dry test tube on the test tube rack and add about 5mL of HCl. Carefully drop a piece of zinc metal and observe briefly. Quickly cover the test tube with a cork and after a minute, insert a lighted match on the mouth of the test tube. A “Pop” indicates the presence of hydrogen.
Pour 5mL of CuSO4 in a clean test tube and add a piece of zinc metal. Let it stand in the rack for five minutes. Pour 5mL of CuSO4 in another test tube. Using a pipette, transfer the solution of the first test tube into another clean one. Observe the first one and the fresh one.
D. Double Replacement: Pour 2mL of zinc acetate in a clean test tube and add 2mL of Na3PO4. Observe what happens.
Pour 5mL of Na2S in a clean test tube and add 1mL of HCl. Observe what happens.
INTRODUCTION Chemical changes are results of chemical reactions. All chemical reactions involve a change in substance and a change in energy. They are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products. There are different types of chemical reaction classified into 4 general types, namely, Synthesis, Decomposition, Single Replacement and Double Replacement.
METHODOLOGY
A. Synthesis: Place an evaporating dish near the burner. Using a test tube holder, examine and hold a magnesium ribbon near the burner flame until it burns. When it stops burning, put what is left on the evaporating dish. In a clean and dry test tube, mix 1g of P2O5 and 5mL distilled water. Mix well and observe. Add a drop of litmus indicator in the test tube and observe the color change.
B. Decomposition: Mount a clean and dry test tube on an iron stand and place 5g of CuCO3. Attach the open end of the balloon on the test tube and heat CuCO3 for about five minutes. Observe the color change and the balloon.
C. Single Replacement: Stand a clean and dry test tube on the test tube rack and add about 5mL of HCl. Carefully drop a piece of zinc metal and observe briefly. Quickly cover the test tube with a cork and after a minute, insert a lighted match on the mouth of the test tube. A “Pop” indicates the presence of hydrogen.
Pour 5mL of CuSO4 in a clean test tube and add a piece of zinc metal. Let it stand in the rack for five minutes. Pour 5mL of CuSO4 in another test tube. Using a pipette, transfer the solution of the first test tube into another clean one. Observe the first one and the fresh one.
D. Double Replacement: Pour 2mL of zinc acetate in a clean test tube and add 2mL of Na3PO4. Observe what happens.
Pour 5mL of Na2S in a clean test tube and add 1mL of HCl. Observe what happens.