LAB DEMO ACTIVITIES

1. LAB DEMOACTIVITIES Aim: To find out the different signs of a chemical change. 1.Blue Bottle 2. Foam Column Solid Reaction Flame Tests Burning Magnesium Carbon Pillar Skills Focus: Making Observations Qualitative vs. Quantitative

2. Qualitative observations use your senses to observe the results. (sight, smell, touch, taste and hear.) Quantitative observations are made with instruments such as rulers, balances, graduated cylinders, beakers, and thermometers. These results are measurable.

4. CHEMICAL CHANGES Lab Demos

5. 1. Blue Bottle • Measure 5g Dextrose • Measure 5g NaOH pellets • Add to 250ml water • Place ¼ drop 1% methylene blue • Conical flask • Stopper • Shake the flask until NaOH is dissolved • Wait • 2.Foam Column • Potassium Permanganate (flat spoonful) • Squirt of detergent - enough to cover the KMnO4 • 30-50ml of hydrogen peroxide (slowly add) • 4. Flame Tests • Different solutions of metal salts • Observe what happens when the solution is ignited. 3

6. 5. • 6. Carbon Pillar • 40ml white sugar • H2SO4 • Small beaker (80ml) • Enough of the H2SO4 to cover the sugar

7. Evidence of chemical reactions Part A - Observations

8. Evidence of chemical reactions Part B - Indications of chemical reaction Make a list of all the observations from above that indicates a chemical reaction has taken place.

11. FLAME TESTS Release of Light Energy

12. FLAME COLORS When ignited, metal particles get excited and when it goes back to its ground state release energy in the form of light. Li

14. Metal salts introduced into a flame give off light characteristic of the metal.

16. 1. Blue Bottle • Measure 5g Dextrose • Measure 5g NaOH pellets • Add to 250ml water • Place ¼ drop 1% methylene blue • Conical flask • Stopper • Shake the flask until NaOH is dissolved • Wait • 2.Foam Column • Potassium Permanganate (flat spoonful) • Squirt of detergent - enough to cover the KMnO4 • 30-50ml of hydrogen peroxide (slowly add) • Gas and heat • color change • reversible reactions • 3.BurningMagnesium • 2cm of Mg • Hold in tongs • Ignite • light and change in form; new substance

17. Solid Reaction • 1 test tube containing Potassium Iodide • 1 test tube containing Lead Nitrate • Pour the KI into a conical flask • Carefully lower the test tube of PbNO3 into the flask • Place on stopper • Place on balance and zero • Tilt flask to spill the PbNO3 • change in color • change in state • Carbon Pillar • 40ml white sugar • H2SO4 • Small beaker (80ml) • Enough of the H2SO4 to cover the sugar • Gas formation • change in color • change in state • change in temp

18. SUMMARY • From the 6 demos, the following are signs of a chemical reaction: • These signs are seen in the …. (cite examples from the demos)

19. Assessment

21. SIGNS OF CHEMICAL RXNS Color change - new substances might reflect different colors of light. Heat change - the container may get hotter or colder. Gas produced - bubbles or smoke may be observed. Precipitate formed - an insoluble solid might form in a liquid.

22. ChemicalRXNs

23. Reactants   Products

24. Parts of a rxn:

25. A + B C FORM C A + B SEPARATE SWITCH 1 A + BX AX + B AX + BYAY + BX SWITCH 2

26. Chemical Reaction Mg + O2 +

27. Chemical Reaction Mg + O2 Mg O Bright Light +

28. REACTION OF COPPER POWDER • WORD EQUATION • CHEMICAL EQUATION

29. REACTION OF COPPER POWDER 2Cu + O2 (2CuO) Copper Oxide (2CuO) Pesticide Fungicide