Unit 4 Covalent Bonding Copy

a. NO 2b. NO 3c. NH 4NameDate Due TestDay! to67. Why do most atoms tend to be chemicallybondedother atoms?2018 - 2019CRITICAL THINKINGPretest: Unit 4Covalent BondingThe following is an overview of the concepts, ideas, and problems we have covered in this unit.You are, however,all material covered,if foundherevariesor not! Therefore, be sure to review all your gardlesslength ofa bondworksheets, assignments, handouts, readings, labs, problems, etc. On the day of the test you will want to be welldependingthe typeof bondyouformed.Predictandacquaintedwith theonmaterialand organized,will not wantto wastetime trying to understand an idea or searching forsomeneededinformation.Arriveprepared!compare the lengths of the carbon-carbon bonds inthefollowing molecules. Explain your answer. (Hint:TextReferences:See· Figure2.10)to Chemical Bonding (6.1)IntroductionCovalent Bonding (6.2)·HHH HGeometry (6.5)· Molecular!Naming! Molecular! !Compounds(7.1, pages 215-219)·H- C - C -HH- C C -HH-C C-HKnow the following vocabulary terms listed below: 69. !!acids Formal charge H Hbinary compound hybridization CC 2Hbond Lewisstructure 2H6energy C2H42chemical bond molecular compound covalentbonding molecularWhydoesF generally formcovalent formulabonds with great dipole molecule polarity? multiple bondnonpolar covalent bondpolar covalent bondresonancesingle bondstructural formulaVSEPR theory70. Explain what is wrong with the following Lewis1. Explain what is wrong with the following Lewis structures, then rewrite each one correctly!structures, and then correct each one.a. H-H-.S.::O: .b. H- C O. . -H.:Cl : c.N.: Cl.Cl. :71. Ionic compounds tend to have higher boiling pointsthan covalent substances do. Both ammonia, NH3, andmethane, CH4, are covalent compounds, yet the boilingpoint of ammonia is 130 C higher than that of methane.What might account for this large difference?"1

Practice Problems1.) Draw Lewis dot structures for:aH 2ObCO2cPF3dH 2SeCN-fCF4gC2H3O2(CH3COO-)(you’ve had this one before!)"2

2.) Name each of the following compounds:a.) N2O3.b.) FeP.c.) H3PO4.d.) PBr3.e.) HCl.f.) MgCl2.g.) OF2.3.) Write formulas for the following compounds:a.) aluminum hydroxide.b.) chromium(II) chloride.c.) phosphorus pentoxide.d.) hydrobromic acid.e.) tetraphosphorus decoxide.f.) sulfurous acid.4.) With words and a diagram, describe the bond that occurs between chlorine andhydrogen in HCl. (Note a similar example was done in class Check your notes!)"3

5.) Using the electronegativity values found on the last page of this packet, label each bondbelow as nonpolar covalent, polar covalent, or ionic. For polar covalent bonds, correctly addδ and δ-to indicate the bond’s polarity.a.)H ----- Fb.)N ----- Nc.)N ----- Od.)Mg ---- O.e.)Cl ---- P.f.)S ---- Cl.6.) In terms of bonding, why does the element oxygen always appear as a diatomic element(O2 not just O)? Explain thoroughly, using labeled orbital diagrams in your discussion.7.) Use an orbital diagram to show how carbon creates four identical hybrid orbitals. (Whatare these orbitals called? Why are they called this?)8.) i. Draw a proper Lewis structure for each of the following ions, then circle the one thathas the shortest and strongest N-O bonding.NO2NO3NO ii. Which compound(s) from part i has a N-O bond that is composed of 1 pi bond and1 sigma bond?"4

9.)Valencee- TotalLewis DotStructureMolecular Shape& Bond AngleName d)(with respect to N)(with respect to O)BF3HCOOH(with respect to C)(with respect to the O with2 bonds)10.) Which compound(s) in problem #9 (above) contain polar bonds, but is/are nonpolar due to symmetry?"5

11.) Draw the three resonance structures for the nitrate ion, NO3-.12.) Use Lewis structures and arrows to show the coordinate covalent bonding that formsbetween BF3 and NH3.13.) Use the table below to calculate the energy need to break all the bonds in thefollowing compounds:a. CCl4b. HCOOH""6

14.) Circle the correct answers.1. The common name of SiI4 is tetraiodisilane. What is its molecular compound name?a. silane tetraiodideb. silane tetraiodinec. silicon iodided. silicon tetraiodide2. Which of the following compounds contains at least one pi bond?a. CO2b. CHCl3c. AsI3:::c. S : Si : S:::: :3. The Lewis structure for silicon disulfide is .:a. Si S :b. S Si S:d. BeF2d. : S Si S :4. The central selenium atom in selenium hexafluoride forms an expanded octet. How many electron pairssurround the central Se atom?a. 4b. 5c. 6d. 75. Chloroform (CHCl3) was one of the first anesthetics used in medicine. The chloroform molecule contains26 valence electrons in total. How many of these valence electrons take part in covalent bonds?a. 26b. 13c. 8d. 46. All of the following compounds have bent molecular shapes EXCEPT .a. BeH2b. H2Sc. H2Od. SeH27. Which of the following compounds is NOT polar?a. H2Sb. CCl4c. SiH3Cld. AsH38. Which of the following diatomic gases has the shortest bond between its to atoms?a. HIb. O2c. Cl2d. N215.) Use the concept of Formal Charge to determine which of the following is the most likelystructure for sulfuric acid, H2SO4."7

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64. Draw the Lewis structure for each of the following molecules: a. PCl 3 b. CCl 2F 2 c. CH 3NH 2 65. Draw the Lewis structure for BeCl 2. (Hint: Beryllium atoms do not follow the octet rule.) 66. Draw a Lewis structure for each of the following polyatomic ions and determine their geometries: a. NO 2