CHEMICAL BONDING Warm Up Complete the following chart CompoundType of Bond (I, M, PC, NPC) Conduct Electricity? Dissolve in Water? State of Room Temp? CS 2 PH 3 BaS CCl 2 Br 2 Warm Up Complete the following chart CompoundType of Molecule (I, M, PC, NPC) Conduct Electricity? Dissolve in Water? State of Room Temp? CS 2 Nonpolar Covalent No Gas PH 3 Polar CovalentNoYesLiquid BaS IonicYes Solid CCl 2 Br 2 Polar CovalentNoYesLiquid HOMEWORK REVIEW Todays Objectives Identify and describe the intermolecular forces present in molecules. Rank molecules based on the intermolecular forces involved. Create molecular models of covalent molecules to determine various bond and/or molecule properties. Identify and describe the intermolecular forces present in molecules. May the Forces be with You There Are Three Types of Intermolecular Forces (IMFs): (1) London Dispersion Forces (2) Dipole-Dipole (3) Hydrogen bonding Predict whats involved in each one and how youll differentiate between them. WHOLE CLASS DISCUSSION Rank molecules based on the intermolecular forces involved. Discussion #1 How would you rank the following in order of increasing boiling point based upon IMFs. PH 3 CH 4 CO 2 H 2 O Rank the following in order of increasing boiling point. CH 4 CO 2 PH 3 H 2 O PH 3 Trigonal Pyrimidal / Polar / Dipole-Dipole CH 4 Tetrahedral / Nonpolar / Single Bonds CO 2 Linear / Nonpolar / Double Bonds H 2 O Bent / Polar / Hydrogen Bonding Discussion #2 Which will have a higher melting point? Why? NH 3 or PH 3 Which will have a higher melting point? Why? NH 3 or PH 3 NH 3 will have a higher melting point because it contains Hydrogen Bonding between the H of one molecule and the N of another molecule. (See picture below) PH 3 has dipole-dipole forces. Discussion #3 Water boils at 100 C and H 2 S boils at -60 C, briefly explain why these two molecules have vastly different boiling points despite having similar structures. Water boils at 100 C and H 2 S boils at -60 C, because of the Hydrogen bonding in water between the H of one molecule and the O of another molecule. The Hydrogen bonding gives rise to a HIGHER boiling point. H 2 S contains only dipole-dipole IMFs You Try #1 (INDEPENDENT WORK) Rank the following in order of increasing boiling point. (Be Careful !!) H 2 NH 3 CO You Try Rank the following in order of increasing boiling point. H 2 CO NH 3 H 2 does NOT have H-bonding, only London and has only single bonds within the atom CO also has London BUT also has triple bonds between molecules making BP higher than H 2 NH 3 has Hydrogen, thus highest BP You Try #2 (INDEPENDENT WORK) Rank the following in order of increasing boiling point. F 2 O Cl 2 H 2 0 You Try Rank the following in order of increasing boiling point. Cl 2 F 2 O H 2 0 Cl 2 has London btwn molecules and single within F 2 O has dipole-dipole and single within H 2 0has Hydrogen bonding Create molecular models of covalent molecules to determine various bond and/or molecule properties. Identify the following properties of chemical compounds using geometric models: Bond Type Shape Polarity Get These Supplies From The Front Counter: Molecular Modeling Lab Sheet (1 per person in your group) Molecular Modeling Kit (1 per group) RULES Atoms are typically represented as follows. Your kit may be different. Use the key in the box lid for reference. Element# Bonds Needed For OctetColor C4BLACK H1YELLOW S, O2RED N, P3BLUE Halogens1PURPLE/GREEN/ORANGE BONDSSINGLE = STICK, DOUBLE = 2 SPRINGS, TRIPLE = 3 SPRINGS DO NOT LOOSE THE PIECES You will start on this side of the handout Assignment: Make a model of each molecule listed on Side #1 When youve completed the chart and the models, contact Mr. Hawkins so he can check your work BEFORE moving on to Side #2. You may share the work between members of your group. Everyone should make at least 1 model. Now youre ready for Side #2 You may not have enough pieces to make all the models at once. When you start to run out, call for a check. Next Steps: Clean up your model kits and return to front counter Homework: (1)Pick-up a copy of the Chemical Bonding Flow Chart to begin working on organizing the info in this unit. Note the CORRECTION on Side #2 (next slide) Also note the word bank to be used on each side of the document. (2) Complete the column for IMFs on last nights homework Remember: Unit 4 Test on Monday 10/6/14 P 3 -1 You Will Complete This Tonight HOMEWORK: (1) Unit 4 Graphic Organizer Worksheet (2) IMFs section on last nights homework Unit 4 Test -- Monday