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

10th Grade Chemistry: 1/22/14

Agenda:•Must Do•WWD•Brief Lesson•Lab!!!!

What’s the caption?

WWDPicture Clues….one word, four syllables

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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

How to tell the difference between a molecular and ionic compound

Use the periodic table!

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

Identifying Ionic and Molecular Compounds

Which of the following compounds would you expect to be ionic: N2O, Na2O, CaCl2, SF4?

Which of the following compounds are molecular: CBr4, FeS, P4 O6, PbF2 ?

Which combination is likely to produce an ionic compound?

C and H

S and Cl

Ca and F

Br and I

Xe and F

Which combination is likely to produce an ionic compound?

C and H

S and Cl

Ca and F

Br and I

Xe and F

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”

Useful LinksPolarity Index

Water Solubility DataSolubility TableSolubility Chart

Lab!

•Build the Best BatteryMake 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

Matrix Example

Lab Rules

Lab Rules ContinuedPlease dump waste in the orange bucket

Go easy on the Isopropyl and acetone

Try not to spill!