Chapter 5

Dot Diagrams

  1. Draw dot diagrams for Cl2 and for MgCl2
  1. Which is the correct Lewis dot diagram for carbonyl fluoride, COF2? What is wrong with the other two?
  1. Which is the correct Lewis dot diagram for N2H2? What is wrong with the other two?

Lone Pairs

  1. How many lone pairs of electrons are on the P atom of PCl3?
  1. How many lone pairs of electrons are there on Br in BrF2+?

Multiple Bonds

  1. Which one of these four molecules contains a triple bond: F2, O3, HCN, or H2CO?
  1. Complete the dot diagram for this molecule to determine (a) how many double bonds it has and (b) how many lone pairs of electrons it has.

Resonance

  1. Draw dot diagrams for all resonance forms of the NCO- ion.
  1. Which one of the following is expected to have resonance forms? Explain.
  2. NH4+
  3. HCN
  4. CO
  5. NO2-
  1. Which of the following represents the correct resonance forms for SO2? Explain what is wrong with the sets you did not choose.

Electronegativity

  1. Which element has the lowest electronegativity, and how can you answer this question without looking up electronegativity values?
  2. Mg
  3. Cl
  4. Ca
  5. Br
  1. Using only the periodic table, arrange these sets of atoms in order of increasing electronegativity:
  2. Li, Be, K
  3. O, Si, S
  4. Br, I, Te
  1. Atoms of different elements, each with at least one unpaired electron, come together to form a compound. According to the diagram below:
  1. Which atom is the more electronegative? Explain how you knew.
  1. Which atom has a partial positive charge and why?
  1. Suppose only one of the elements is a metal. Which element is it? Explain how you knew.
  1. What value would you have to calculate to decide if this bond is polar, covalent, or ionic?

Polar Compounds

  1. The phosphorus atom in PCl3 should have a
  2. Partial positive charge
  3. Partial negative charge
  4. 3+ charge
  5. 3- charge

Ionic vs. Molecular

  1. Which of the following substances are ionic and which are molecular? Name each substance. Draw Lewis dot diagrams for each molecular substance and for the anion of each ionic substance.
  2. Cl2
  3. HCl(g)
  4. NaCl
  5. Mg(ClO2)2
  6. CH3OH (methanol)
  7. Fe(NO3)3
  8. Pb(C2H3O2)2

Naming

  1. Give the formula for the following compounds:
  2. Calcium phosphate
  3. Potassium hydrogen phosphate
  4. Magnesium cyanide
  5. Barium chlorate
  6. Give the proper name of these compounds:
  7. Fe2(SO3)3
  8. Au(NO3)3
  9. NaH2PO4
  10. Pb(CH3CO2)2
  11. Give the proper name for each compound and indicate whether it is ionic or polar covalent:
  12. NH4I
  13. Cl2O7
  14. SrCl2
  15. Li2Cr2O7
  1. Complete this table of ionic compounds. Give both old and new names where you can.

Name / Formula
AgNO3
Aluminum selenide
Lithium oxide
Ammonium iodide
CuSO4
KMnO4
Ca(ClO3)2
  1. Complete this table of ionic compounds. Give both old and new names where you can.

Name / Formula
Sodium bicarbonate
Magnesium acetate
Barium hypochlorite
Fe(NO3)3
(NH4)2SO4
Calcium phosphate
Co2(CrO4)3
  1. Complete this table of molecular compounds.

Name / Formula
CdTe
Nitrogen triiodide
SiI4
Bromine trifluoride
Hydroiodic acid
HI (as a pure gas)
S4N4
  1. Complete this table of molecular compounds.

Name / Formula
XeF4
XeF2
Iodine monochloride
Bromine trichloride
Diboron hexahydride
N2O
S4O2