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Homework: Names and Formulas
of Molecular Compounds
Additional Practice

Writing Formulas

  1. In your own words, write down the correct procedure for writing a name for a molecular compound from its formula. Enrich your procedure with examples such as how to name these compounds: NO2, ClO3, ClO, As4O10.
  2. Now do the reverse: How do you write a correct formula given the name of a molecular compound?
Use the names to construct a correct molecular compound formula.
  1. chlorine monoxide
  2. oxygen difluoride
  3. boron phosphide
  4. dinitrogen monoxide
  5. nitrogen trifluoride
  6. sulfur tetrachloride
  7. xenon trioxide
  8. carbon dioxide
  9. diphosphorous pentoxide
  10. phosphorous trichloride
  11. sulfur dioxide
  12. bromine pentafluoride
  13. disulfur dichloride
  14. boron trifluoride
  15. bismuth trichloride
  1. tetraarsenic decoxide
  2. silicon tetrachloride
  3. krypton difluoride
  4. chlorine dioxide
  5. silicon dioxide
  6. boron trichloride
  7. dinitrogen pentasulfide
  8. carbon monoxide
  9. sulfur trioxide
  10. dinitrogen trioxide
  11. dinitrogen monoxide
  12. xenon hexafluoride
  13. sulfur hexafluoride
  14. phosphorous pentachloride
  15. nitrogen monoxide

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    Lewis Diagrams

    For each of the following atoms write down the number of valence e-s. Also, draw the Lewis dot diagram. For example, Magnesium (Mg) has two valence electrons and has a Lewis diagram that looks like this: Mg:

    1. Rb
    2. P
    3. Ga
    4. Te
    1. C
    2. Ba
    3. I
    4. Ne
    1. In your own words explain how to find the correct number of valence electrons from an element’s position in the periodic table.

    Writing Names

    Name the following compounds.

    1. As4O10
    2. BrO3
    3. BN
    4. N2O3
    5. NI3
    6. SF6
    7. XeF4
    8. PCl3
    9. CO
    10. PCl5
    11. P2O5
    12. S2Cl2
    13. ICl2
    14. SO2
    15. P4O10
    1. UF6
    2. OF2
    3. ClO2
    4. SiO2
    5. BF3
    6. N2S5
    7. CO2
    8. SO3
    9. XeF6
    10. KrF2
    11. BrCl5
    12. SCl4
    13. PF3
    14. XeO3
    15. OsO4

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    Text Review

    Answer the following questions using complete sentences.
    1. What is a diatomic molecule?
    2. Which elements exist in pure form as diatomic molecules? (Remember, you must memorize these!)
    3. What are some compounds that are diatomic molecules?
    4. What is the difference between a compound and an element?
    5. What are the characteristics of metallic elements? Where are they found in the periodic table?
    6. Describe the properties of non-metals. Where are they found in the periodic table?
    1. What kinds of elements are involved in most molecular compounds?
    2. Describe the behavior of electrons in a covalent bond between atoms. How do the electrons keep the atoms bound together?
    3. Compare and contrast the types of elements found in the chemical formulas of molecular compounds and ionic compounds.
    4. What are the physical characteristics or properties which differentiate ionic compounds from molecular compounds?

    1. What is the law of constant composition of chemical compounds?
    2. Calculate the ratio of oxygen to nitrogen in the following compounds.
      N2O (28.0 g N, 16.0 g O)

      NO (14.0 g N, 16.0 g O)

      NO2 (14.0 g N, 32.0 g O)

      N2O4 (28.0 g N, 64.0 g O)

    3. Use the ratios you calculated above to identify the following compounds, based on their compositions.
      A compound analyzed to have
      5.6 g N and 3.2 g O

      A compound analyzed to have
      1.17 g N and 2.67 g O
    1. For each formula in the last two problems, write the proper names of the compounds.
    2. Write the formula and calculate the formula mass (using a periodic table) for the compounds in numbers 3. through 13. on the first page of this assignment.
    3. Calculate the formula mass for each of the following compounds, some of which are ionic.
      NaCl                           H2O

      Mg(OH)2                           Na2SO4

      BaCO3                           Al2(CO3)3
    This homework belongs with the Chemical Nomenclature of Molecular Compounds group activity.
    ChemTeam Additional Naming Information and Practice
    (has lots of exercises with answers)
    Last updated: Jan 06, 2023       Home