Unit 4:Chemical Bonding Practice Packet

Name: KEYUnit 4:Chemical Bonding Practice Packet1. I can state the three typesof chemical bonds.The three types of chemical bonds are:ionic , covalent , andmetallic .2. I can state the number ofvalence electrons that an atomattains to be most stable.3. I can state the two typesof compounds.Atoms are most stable when they have 8 valence electrons.The two types of compounds are ionic andcovalent (molecular) .Definition:ionic bond4. I can define ionic bond,covalent bond, and metallic bondin terms of the types of elements(metals, nonmetals) from whichthey are formed.covalent bondmetallic bondDefinition:In an ionic bond, the valence electrons of the metal are5. I can define ionic andcovalent bonds based on whathappens to the valence electrons.transferred to the nonmetal so that each atom attainsa stable octet (like noble gases).In a covalent bond, the valence electrons of the two nonmetalsare shared so that each atom attains a stable octet (likenoble gases).6. I can explain TICS as itrelates to chemical bonding.TICS stands for transferred ionic, covalent shared .It helps me remember what happens to the electrons in each type of bond.Explain, in terms of valence electrons, why the bonding in methane (CH4) issimilar to the bonding in water (H2O).7. In terms of valenceelectrons, I can find similaritiesand differences between thebonding in several substances.In both CH4 & H2O the valence electrons are shared to form covalent bonds.Explain, in terms of valence electrons, why the bonding in HCl is different thanthat bonding in NaCl.In HCl the valence electrons are shared to form a covalent bond. In NaCl,the valence electrons are transferred from the Na to the Cl to form an ionicbond.

Draw Lewis dot diagrams for the following ionic compounds.8. I can draw a Lewis dotdiagram to represent an ioniccompound.LiBrCaCl 2Draw Lewis dot diagrams for the following molecular substances.9. I can draw a Lewis dotdiagram to represent a molecular(covalently bonded) compound.H2 OCO 2I2CH4In a single covalent bond, 2 electrons are shared.10. I can state the numberof electrons that are shared insingle and multiple covalentbonds.In a double covalent bond, 4 electrons are shared.In a triple covalent bond, 6 electrons are shared.6Lewis dot diagrams for ionic compounds have brackets because11. I can explain why theLewis dot diagrams of ioniccompounds have brackets and theLewis dot diagrams of molecularcompounds do not.the elements involved in the bond have charges .Lewis dot diagrams for molecular compounds do NOT have brackets becausethe electrons are shared and there are no charges .12. I can state the type ofbonding that occurs in thepolyatomic ions (Reference TableE) and explain why they have thattype of bonding.13. Given the chemicalformula for a compound, I candetermine the type(s) of bondingin the compound.Polyatomic ions have covalent bonding becausenonmetals are sharing valence electrons .State the type(s) of bonding in the following compounds:NaCl ionic CO covalentHg metallic Na3PO4 ionic & covalent

14. I can explain and applythe meaning of BARF as is appliesto chemical bonding.BARF stands for “broken absorbed, released formed”This means that when a bond is FORMED, energy is releasedand when a bond is BROKEN, energy is absorbed .Given the balanced equation:N N ----- N2Which statement describes the process represented by this equation?A) A bond is formed as energy is absorbed.B) A bond is formed as energy is released.C) A bond is broken as energy is absorbed.D) A bond is broken as energy is released.15. I can explain thedifference between a polarcovalent bond and a nonpolarcovalent bond in terms of thetypes of nonmetals involved.Polar covalent bonds are formed when two differentnonmetals share electrons unevenly.Nonpolar covalent bonds form when two of the samenonmetals share electrons evenly.16. I can explain how todetermine the degree of polarityof a covalent bond.The degree of polarity of a covalent bond is determined by the17. I can explain why onecovalent bond is more or less polarthan another covalent bond, basedon electronegativity difference.Explain, in terms of electronegativity difference, why the bond between carbonand oxygen in a carbon dioxide molecule is less polar than the bond betweenhydrogen and oxygen in a water molecule.electronegativity difference between theelements. .The difference in electronegativity between carbon and oxygen is less thanthe difference in electronegativity between hydrogen and oxygen so the CObond is less polar.18. I can define symmetricaland asymmetrical.Definition:symmetrical – molecule that has the at least two lines of symmetryasymmetrical – molecule that does not have lines of symmetry19. I can state, in order, thethree questions that are asked todetermine if a MOLECULE is polaror nonpolar.When determining if a MOLECULE is polar or non-polar, the first question toask is ”Is there more than one polar bond?”When determining if a MOLECULE is polar or non-polar, the second question toask is ”Does the central atom have unshared pairs of electrons?”

When determining if a MOLECULE is polar or non-polar, the third question toask is ”Is the molecule symmetrical?”20. I can explain and applythe meaning of SNAP as it appliesto determining molecule polarity.SNAP means ”symmetrical nonpolar, asymmetrical polar”Why is a molecule of CH4 nonpolar even though the bonds between thecarbon and hydrogen are polar?A) The shape of the CH4 molecule is symmetrical.B) The shape of the CH4 molecule is asymmetrical.C) The CH4 molecule has an excess of electrons.D) The CH4 molecule has a deficiency of electrons.Explain, in terms of charge distribution, why a molecule of water (H2O) ispolar.A water molecule has asymmetrical distribution of charge.21. I can determine if amolecular is polar or nonpolar.Determine which molecules are polar and which are nonpolar. Justify youranswer.H2 Opolar; central atom hasunshared electronsI2nonpolar; no polar bonds22. I can explain and applythe expression “like dissolves like”and give an example.CO2nonpolar; symmetricalCH4nonpolar; symmetrical“Like dissolves like” meansif two substances have the same polarity (polar or nonpolar), they willdissolve in one anotherAn example of “like dissolving like” is ammonia dissolving in waterExplain, in terms of molecular polarity, why ammonia is more soluble thanmethane in water at 20oC at standard pressure.Both ammonia and water are polar so ammonia dissolves in water. Methaneis nonpolar and therefore will not dissolve well in polar water.

23. I can defineintramolecular forces andintermolecular forces and giveexamples of each.Definition:Intramolecular forces – forces of attraction within a moleculeExamples: ionic bonds and covalent bondsIntermolecular forces – forces of attraction between moleculesExamples: dipole-dipole, London dispersion forces, hydrogen bonds24. I can list theintramolecular forces fromSTRONGEST to WEAKEST.25. I can list theintermolecular forces fromSTRONGEST to WEAKEST.Strongest covalent bonds ionic bonds WeakestStrongest hydrogen bonds dipole-dipole London dispersion forces Weakest26. I can state 8 physicalproperties of substances that aredependent on the type of bondingin the substance and the strengthof the IMF.Eight physical properties that are dependent on the type of bonding and thestrength of the IMF are:1. physical state 2. melting point3. boiling point 4. conductivity5. vapor pressure 6. malleability7. solubility 8. hardness27. I can state therelationship between polarity andIMF strength.As the polarity of the molecule increases , the strengthof the IMF increases .28. I can state therelationship between size of themolecule and IMF strength.As the size of the molecule increases , the strengthof the IMF increases .29. Given the physical stateof some substances, I can comparethe relative strength of the IMF.At STP, iodine (I2) is a crystal and fluorine (F2) is a gas. Compare the strengthof the IMF in a sample of I2 at STP to the strength of the IMF in a sample of F2at STP.F2 has weaker IMF than I2.

30. Given the boiling points(or freezing points) of somesubstances, I can compare therelative strength of the IMF.At STP, CF4 boils at -127.8oC and NH3 boils at -33.3oC. Which substance hasstronger IMF? Justify your answer.NH3 has stronger IMF because NH3 has a higher boiling point.31. I can explain and applythe meaning of “Hydrogen bonding “Hydrogen bonding is FON” means Hydrogen bonding occurs when theis FON”.molecule contains fluorine, oxygen, or nitrogen.Which compound has hydrogen bonding between its molecules?A) CH432. I can state 5 physicalproperties of ionic substances.B) CaH2C) KNO3D) H2OFive physical properties of ionic substances are:1. have ionic bonding2. have high mp3. have high bp4. low vapor pressure5. conduct electricity as liquids or aqueous33. I can identify a substanceas “ionic” based on its properties.A solid substance was tested in the laboratory. The results are shown below.*dissolves in water*is an electrolyte* has a high melting pointBased on these results, the solid substance could beA) HgB) AuClC) CH4D) C12H22O11Based on bond type, which compound has the highest melting point?34. I can state 5 physicalproperties of molecularsubstances.A) CH4B) C12H22O11C)NaClD) C5H12Five physical properties of molecular substances are:1. have covalent bonding2. have low mp

3. have low bp4. high vapor pressure5. do NOT conduct electricity35. I can identify asubstance as “molecular” based onits properties.

bonding in several substances. Explain, in terms of valence electrons, why the bonding in methane (CH4) is similar to the bonding in water (H2O). In both CH4 & H2O the valence electrons are shared to form covalent bonds. Explain, in terms of valence electrons, why the bonding in HCl is different than that bonding in NaCl.