Chemistry - Chp 8 - Covalent Bonding - Study Guide
Name __________________________________________ Date ___________________ Chapter 8 Study Guide Covalent Bonding• What is a covalent bond?• What are the characteristics of molecular compounds (covalently bonded compounds) Characteristics of Ionic and Covalent Compounds Characteristics Ionic compound Covalent compound Representative element Formula unit Bond formation Transfer of one or more electrons between atoms Type of elements Metallic and nonmetallic Physical state Solid Melting point High (usually above 300 deg. Celcius) Solubility in water Usually high Electrical conductivity of Good conductor aqueous solution• Know how to write the Lewis electron dot structure for a molecular compound given its molecular formula.• The trick part is figuring out how many bonds to draw. It’s easy if you follow these steps.1. Count the number of ____________________________________________________2. Subtract that number from ________________________________________________3. Divide your answer by _________4. That number equals _____________________________________________________5. Draw the structure with the correct number of bonds and don’t forget to make sureevery octet is full.
Example Questions(Use the steps above to figure out how many bonds there are in each molecule, then drawthe structures of each of the molecules.)1.) Br22.) CH43.) H204.) S25.) As2• Know how to draw resonance structuresExample Question(Draw all the possible resonance structures for the molecule below.)O3• What is a polar bond?• Know how to use Table S to determine the electronegativity difference and the chart below to determine what kind of bond will be made.
Electronegativity Differences and Bond Types Electronegativity Difference Range Most Probably type of bond 0.0-0.4 0.4-1.0 1.0-2.0 > 2.0Example Problems1.) What kind of bond will be produced between H and Cl?2.) What kind of bond will be produced between N and N?3.) What kind of bond will be produced between Li and Br?• What is a polar molecule?• Know how to denote the partial charges of a polar bond on a molecule with symbolsExample ProblemsFirst draw the structure of each molecule, then using symbols, write the partial chargescause by polar bonds on each molecule. 1.) HCl 2.) H20 3.) CF4 4.) CO2• What is a polar molecule? (Explain why a molecule which has polar bonds can either be polar or non polar)
Example problems1.) Is CO2 polar? Why? (use a drawing of the molecule in your explanation)2.) Is H2C polar? Why? (use a drawing of the molecule in your explanation)• Rank the strengths of the intermolecular attraction forces126.96.36.199.***This test will only be 12-15 questions, due to the shortened class time tomorrow. Thisreview sheet will have the basis of how to answer each question guaranteed. Know thisreview sheet and you’ll do great on the test******Even though I don’t think you’ll need it, I will allow offer you the opportunity to usethis review sheet on tomorrows test. However if you choose to use it, the highest gradeyou may receive will be a 90%***