1. Learning Target: Design and Plan a Scientific Investigation to Compare the Structure of Substances at the Bulk Scale to Infer the Strength of Electrical Forces Between Particles….and… Communicate scientific and technical information about why the molecular level structure is important in the functioning of designed materials Must Do: Write a brief statement about your knowledge of molecular (covalent) vs. ionic compounds 10 th Grade Chemistry: 1/22/14 Agenda: Must Do WWD Brief Lesson Lab!!!! What’s the caption?

3. WWD Picture Clues….one word, four syllables + + +

4. Polarity! Definition Noun (1) The presence of or having distinct and opposite poles (2) The condition of having contrasting properties or direction (3) (chemistry) The tendency of forming distinctive opposing charges based on the orientation of chemical bonds and spatial structure of the molecule

6. How to tell the difference between a molecular and ionic compound Use the periodic table!

7. Compounds and Chemical Formulas Molecule - A single particle, contains two or more nonmetal atoms; covalently bonded Formula Unit – a particle containing a metal with a nonmetal; ionicly bonded Chemical formulas – give the number of atoms of each element in a compound

8. Identifying Ionic and Molecular Compounds Which of the following compounds would you expect to be ionic: N 2 O, Na 2 O, CaCl 2, SF 4 ? Which of the following compounds are molecular: CBr 4, FeS, P 4 O 6, PbF 2 ?

9. Which combination is likely to produce an ionic compound? C and H S and Cl Ca and F Br and I Xe and F

10. Which combination is likely to produce an ionic compound? C and H S and Cl Ca and F Br and I Xe and F

11. Solubility Important concept for the lab Do you expect that ionic compounds will dissolve in non- polar, somewhat polar, or polar liquids? Will molecular compounds dissolve in non-polar, somewhat polar or polar liquids? Alcohol in water? Acetone in water? Sugar in water? Sugar in Acetone? Mineral oil in water, acetone, alcohol? In general “like dissolves like”

12. Useful Links Polarity Index Water Solubility Data Solubility Table Solubility Chart

13. Lab! Build the Best Battery Make a matrix of materials and measure the electrical properties of your cell Try to get the most voltage out of your Cell (cells….this is a hint). The winning group gets to do a victory dance

14. Matrix Example

15. Lab Rules

17. Lab Rules Continued Please dump waste in the orange bucket Go easy on the Isopropyl and acetone Try not to spill!