General Chemistry____Flame Spectrum.pptx

General Chemistry____Flame Spectrum.pptx

1. ACTIVITY IN FOCUS DEPARTMENT OF EDUCATION Module 1: Electronic Structure of Matter Activity 1: FlameTest Objectives of the Activity: Determine the characteristic colors that metal salts emit; and Relate the colors emitted by metal salts to the structure of the atom.

2. ACTIVITY IN FOCUS DEPARTMENT OF EDUCATION Video on fireworks display

3. ACTIVITY IN FOCUS DEPARTMENT OF EDUCATION Why do fireworks emit different colors ?

4. Pre-lab Discussion DEPARTMENT OF EDUCATION Precautions: Wear goggles, gloves and a safety apron while performing the activity, Do this activity in a well-ventilated area. Hydrochloric acid is corrosive. Ethanol is flammable and should therefore be handled with care unless necessary, keep it away from fire. Be careful to extinguish all matches after use.

5. ACTIVITY IN ACTION DEPARTMENT OF EDUCATION Materials: nichrome wire alcohol lamp watch glass (bottle crown) medicine dropper water Calcium chloride Sodium chloride Copper (II) sulfate Potassium chloride Strontium chloride safety matches

6. ACTIVITY IN ACTION DEPARTMENT OF EDUCATION Procedure: Dissolve a small amount of each substance in 2 drops of water in the watch glass or tansan . Dip the nichrome wire loop in the solution and heat at the hottest part of the flame. Observe the predominant color of the flame and record your observation

7. ACTIVITY IN ACTION DEPARTMENT OF EDUCATION Procedure: 4. Repeat procedure No. 2 for each solution.

8. ACTIVITY IN ACTION DEPARTMENT OF EDUCATION Procedure: 5. Write your observation in a table similar to the one below. Metal Salt Tested Element Producing Color Color of the Flame Strontium chloride Strontium Calcium chloride Calcium Sodium chloride Sodium Potassium chloride Potassium Copper (II) sulfate Copper Table 1. Color of the Flame of Metal Salts

9. ACTIVITY IN ACTION DEPARTMENT OF EDUCATION Q1. Why do you think are there different colors emitted? Formative Assessment Q2. What particles in the heated compounds are responsible for the production of the colored light? Q3. How did the scientists explain the relationship between the colors observed and structure of the atom?

10. ACTIVITY IN ACTION DEPARTMENT OF EDUCATION Q4 : Explain how your observation in Activity 1 relates to Bohr’s model of the atom. You can explain using an illustration . Q5: Which illustration below represents the energy of the electron as described by Bohr? Explain your answer. a. b.

11. POST LAB DISCUSSION DEPARTMENT OF EDUCATION Q1. Why do you think are there different colors emitted? Formative Assessment

12. POST LAB DISCUSSION DEPARTMENT OF EDUCATION Q1. Why do you think are there different colors emitted? Formative Assessment A1: Metal salts emitted different colors because of the absorption of heat from the flame.

13. POST LAB DISCUSSION DEPARTMENT OF EDUCATION Q2. What particles in the heated compounds are responsible for the production of the colored light? Formative Assessment

14. POST LAB DISCUSSION DEPARTMENT OF EDUCATION Q2. What particles in the heated compounds are responsible for the production of the colored light? Formative Assessment A2. The valence electrons in the metallic element are responsible for the production of colored light.

15. ACTIVITY IN ACTION DEPARTMENT OF EDUCATION Q3. How did the scientists explain the relationship between the colors observed and structure of the atom? Formative Assessment

16. ACTIVITY IN ACTION DEPARTMENT OF EDUCATION Q3. How did the scientists explain the relationship between the colors observed and structure of the atom? Formative Assessment A3. The color observed is an indication that definite energy transformations occur inside the atom emitting light. It follows that electrons must occupy orbits of fixed energy.

17. Limitations of Flame Test DEPARTMENT OF EDUCATION It cannot detect low concentrations of almost all ions. The intensity of the visible light differs from one sample to another. For example, the yellow emission from sodium is much brighter than the red emission from the same amount of lithium.

18. Limitations of Flame Test DEPARTMENT OF EDUCATION Contaminants affect the test results. Sodium, in particular, is present in most compounds and will color the flame. Sometimes a blue glass is used to filter out the yellow of sodium. The test cannot differentiate between all elements. Several metals produce the same flame color . Some compounds do not change the color of the flame at all.

19. APPLICATION DEPARTMENT OF EDUCATION

20. DEPARTMENT OF EDUCATION SUMMATIVE ASSESSMENT   Which combination describes the flame color of the compound when heated? Sodium chloride – orange copper (II) sulfate – violet potassium chloride – blue boric acid - red

21. DEPARTMENT OF EDUCATION READINGS LeMay, E.H. Jr., Robblee, K.M., Brower, H., Douglas C. (1996). Chemistry Connections to Our Changing World . New Jersey: Prentice Hall, Inc. Magno, M., et. al. (2001). Practical Work in High School Chemistry Sourcebook for Teachers. Quezon City: UP National Institute for Science & Mathematics Education Development   Silberberg, M. (1996). Chemistry: The Molecular Nature of Matter and Change . St. Louis: Mosby. Wilbraham, A.C., Staley, D. D., Matta, M. (1997). Chemistry , 4 th ed. New York: Addison-Wesley Pub.   Wilbraham, A.C., Staley, D.D., Matta, M.S. & Waterman, E.L. (2007). Chemistry , Teacher ’ s Ed. Boston, Massachusetts:Pearson, Prentice Hall, Inc.  

22. DEPARTMENT OF EDUCATION READINGS chemed.chem.purdue.edu http://curriculum.nismed.upd.edu.ph http://www.smallscalechemistry.colostate.edu/PowerfulPictures/ChemicalBonding.pdf http://www.chemguide.co.uk/atoms/bonding/electroneg.html http://chemistry.about.com/od/electronicstructure/a/Octet-Rule.htm http://www.edu-resource.com/chemistry/what-are-ionic-compounds.php http://misterguch.brinkster.net/ionic.html