Chem I: TYPES OF CHEMICAL BONDS #1 Name____________________ Period________ PART 1: Three Types of Bonds 1. In nature, most atoms are joined to other atoms by chemical bonds. The periodic table can help you determine what type of bonds elements will make. a. Bond between Metal and Nonmetal = ___________________________________________ b. Bond between Nonmetal and Nonmetal = ________________________________________ c. Bond between Metal and Metal = ______________________________________________ Using your periodic table, classify the following compounds as ionic, covalent or metallic: a. CaCl2 g. CaF2 b. Cu (copper) h. HCl c. CO2 i. Cu-Zn (brass) ____________ d. H2O j. Fe (iron) ____________ e. MgO k. PCl2 ____________ f. C6H12O6 (glucose) l. NH4Cl ____________ PART 2: Electronegativity 2. Atoms form bonds to ___________________________________________ _____________________________________________________________ 3. We can figure out for sure what type of bond will form between atoms by looking at electronegativities. a. An ionic bond will form between atoms who’s electronegativities differ by (more/less than) ___________. b. A covalent bond will form between atoms who’s electronegativities differ by (more/less than) ___________. Which type of bond will form between the following atoms? Atom 1 – Electronegativity Fe = Atom 2 – electronegativity O= Fr = Br = Au = As = Li = Cl = Na = Pd = Mg = N= Electronegativity Difference Type of Bond PART 3: Lewis Dot Diagrams a) Write the shorthand electron configuration for the element. b) Determine how many valence electrons. (circle the valence electrons) c) Draw a Lewis Dot Diagram. d) Based on the atoms valence electrons, write the charge that atom would have (it’s oxidation number), when it gains/loses electrons to become stable. EXAMPLE: Valence Electrons: ___2___ [Ne]3s 2 .. Mg Oxidation number: ____Mg2+___ 1. Valence Electrons: _______ Na Oxidation Number: __________ 2. Valence Electrons: _______ F Oxidation Number: __________ 3. Valence Electrons: _______ K Oxidation Number: __________ 4. Valence Electrons: _______ S Oxidation Number: __________ 5. Valence Electrons: _______ Al Oxidation Number: __________ 6. Valence Electrons: _______ O Oxidation Number: _________ Chem I: IONIC BONDING #2 Ionic Bonding occurs when a metal transfers one or more electrons to a nonmetal in an effort to attain a stable octet of electrons. For example, the transfer of an electron from sodium to chlorine can be depicted by a Lewis dot diagram. Na + Cl → Na+Cl- Calcium would need two chlorine atoms to get rid of its two valence electrons. Cl + Ca + Cl → Ca+2Cl −𝟐 Part I: Show the transfer of electrons in the following combinations. 1. K + F 2. Mg + I 3. Be + S 4. Na + O 5. Al + Br Part II Draw the Lewis structures for each atom, draw arrows to show the transfer of electrons, and then write the chemical formula (include the charge for each ion). Remember that more than one element may be needed in order for the ionic compound to be stable. 1. Mg + O Mg + O 8. Al + Cl Mg+2O-2 2. Na + S 9. Li + I 3. Mg + F 10. K + S 4. K + O 11. Ca + S 5. K + Cl 12. Ca + Br 6. Ba + F 13. Ca + N 7. Cs + N 14. Rb + F Chemistry I: COVALENT BONDING #3 Drawing the structure formulas for the MOLECULES below: 1. Count the total number of valence e-. 2. Determine the central atom. The following are guides: Often the unique atom (only one of it) is the central atom. Or put the least electronegative element in the middle. 3. Arrange the other atoms around the central atom creating a skeleton. 4. Connect all bonded atoms in the skeleton with one bond. 5. Subtract the number of electrons already used for the single bonds; two for each bond. 6. Distribute the remaining electrons in pairs around the atoms, trying to satisfy the octet rule. Assign them to the most electronegative atom first. 7. If you run out of electrons before all atoms have an octet of electrons, you need to form double or triple bonds. 8. If you have extra electrons and all of the atoms have an octet, put the extra electrons on the central atom in pairs. 1. Br2 Br Br 3. SiH4 Total # of valence electrons _ 14___ 14 -2 12 -12 0 Total # of valence electrons_______ 2. CH3Br Total # of valence electrons_______ 4. H3P Total # of valence electrons_______ 5. O2 Total # of valence electrons_______ 6. CO Total # of valence electrons_______ 7. N2 Total # of valence electrons_______ 9. SiO2 8. SeO3 Total # of valence electrons_______ Total # of valence 10. SCl4 Total # of valence electrons_______ 12. TeF6 Total # of valence electrons_______ electrons_______ 11. ICl5 Total # of valence electrons_______ 13. Only if we get to polyatomic ions NO3 - 1 Total # of valence electrons_______ 14. Only if we get to polyatomic ions PO4-3 Total # of valence electrons_______ Chem I: SPECIAL COVALENT BONDS #4 Diatomic Molecules & Polyatomic Molecules PART I: Using your notes, write the definition of the following, include a statement on what force holds the atoms together (sharing electrons or transferring electrons): Ionic Bond: Covalent Bond: Directions: Classify the following compounds as (I) ionic (metal + nonmetal) (C) covalent (nonmetal + nonmetal) (D) diatomic molecules (two of the same atom bound together) (P) polyatomic ion (groups containing more than two elements covalently bonded together that carry an overall charge. ) 1. CaCl2 11. N2 2. CO2 12. NH4Cl 3. H2O 13. HCl 4. BaSO4 14. KI 5. K2O 15. NaOH 6. NaF 16. NO2 7. Na2CO3 17. AlPO4 8. CH4 18. FeCl3 9. O2 19. P2O5 10. LiBr 20. N2O3 PART II: Diatomic molecules are two of the same atom bound together. These atoms do not exist alone in nature because they are extremely reactive. They always will come in pairs. Elements that form diatomic molecules are: Br, I, N, Cl, H, O, F They are called the BIG SEVEN. *YOU MUST MEMORIZE THESE DIATOMIC MOLECULES. 1. On the periodic table below, color the diatomic molecules. 2. Draw the structure formula (using Lewis Dot drawings) for the following diatomic molecules. 2. Br2 Total # of valence electrons _ 14___ Br Br 3. I2 4. O2 4. Cl2 Total # of valence electrons_______ 14 -2 12 -12 0 Total # of valence electrons_______ Total # of valence electrons_______ 5. H2 6. N2 Total # of valence electrons_______ Total # of valence electrons_______ PART III: Polyatomic ions are groups of covalently bonded atoms that carry an overall charge. Drawing the structure formulas for the MOLECULES below: Remember… Constructing Dot Diagrams for the polyatomic ions is the same as constructing Dot Diagrams for molecules, except the difference in charge (+ or -) must be accounted for. STEPS: 1. Count the total number of valence e-. 2. Determine the central atom. The following are guides: Often the unique atom (only one of it) is the central atom. Or put the least electronegative element in the middle. 3. Arrange the other atoms around the central atom creating a skeleton. 4. Connect all bonded atoms in the skeleton with one bond. 5. Subtract the number of electrons already used for the single bonds; two for each bond. 6. Distribute the remaining electrons in pairs around the atoms, trying to satisfy the octet rule. Assign them to the most electronegative atom first. 7. If you run out of electrons before all atoms have an octet of electrons, you need to form double or triple bonds. 8. If you have extra electrons and all of the atoms have an octet, put the extra electrons on the central atom in pairs. 9. *Polyatomic Ions: Account for the charge (+ or -). Place structure in brackets with the charge indicated on outside. 1. NH3 Total # of valence electrons # of electrons involved in single bonds _______ _______ _________________________________________ 2. NH4 + Number of electrons to distribute _______ *For Polyatomic Ions: what is the charge _______ Total # of valence electrons # of electrons involved in single bonds _______ _______ _________________________________________ 3. SO3 2- Number of electrons to distribute _______ *For Polyatomic Ions: what is the charge _______ Total # of valence electrons # of electrons involved in single bonds _______ _______ _________________________________________ Number of electrons to distribute _______ *For Polyatomic Ions: what is the charge _______ 4. HI Total # of valence electrons_______ 8. SiO2 Total # of valence electrons_______ 5. CO2 Total # of valence electrons_______ 9. PO4 -3 Total # of valence electrons_______ 6. NO-3 Total # of valence electrons_______ 10. SCl4 Total # of valence electrons_______ 7. H3O+ Total # of valence electrons_______ 11. N(CH3)3 Total # of valence electrons_______ Chemistry I: VSEPR-MOLECULAR SHAPES #5 Using the VSEPR Theory, name and sketch the shape of the following molecules. STEPS: 1. Count the total number of valence e-. 2. Draw the Lewis Dot Structure 3. Determine the # of lone pairs on central atom Molecule Formula 1. N2 2. H2O 3. CO2 4. NH3 5. CH4 6. SO3 Valence Electrons *Show math* Draw Lewis Dot Structure 4. Write the VSEPR Formula (eg. AX2) 5. Draw the Ball & Stick Model 6. Write the name of the geometric shape # of lone pairs on central atom VSEPR Formula Draw Geometric Shape (Ball & Stick Method) Name of Geometric Shape Molecule Formula 7. HF 8. CH3OH 9. H2S 10. I2 11. CHCl3 12. O2 Valence Electrons *Show math* Draw Lewis Dot Structure # of lone pairs on central atom VSEPR Formula Draw Geometric Shape (Ball & Stick Method) Name of Geometric Shape