Module 5 Problem Set Quiz

Module 5 Problem Set

• Question 1

  What will be the charge of the ion formed from each of these atoms? Explain your answer.

  As₃₃, Ge₃₂

  Correct Answer

   

   

• Question 2

  Using the electronegativity values from the equation bank, show the determination of the polarity of each different type of bond in the following molecules:

  

  Correct Answer

  1) Cl-O bond electronegativity difference = 3.5 - 3.0 = 0.5       

      (1.6 - 0.5 bond is Polar)

  H-O bond electronegativity difference = 3.5 - 2.1 = 1.4            

     (1.6 - 0.5 bond is Polar)

  2) C≡N bond electronegativity difference = 3.0 - 2.5 = 0.5       

    (1.6 - 0.5 bond is Polar)   

  H-C bond electronegativity difference = 2.5 - 2.1 = 0.4 

    (< 0.5 bond is Nonpolar)      

• Question 3

  Write Lewis dot structures for the following molecules:

  NH₃, SO₂, CH₃OH, HNO₂, N₂, CH₂O

  Correct Answer

  

   

• Question 4

  Determine and explain for each material below (a) Electron geometry of a central atom, (b) Hybridization of the Central atom, (c) Shape of the Molecule, (d) Molecular Polarity

  1.) PH₃

  2.) HCN

  Correct Answer

  1.)  PH₃          4 Groups of electrons around P = Tetrahedral Electron Geometry

                          Tetrahedral Electron Geometry = sp³ Hybridization of P

                          3 atoms around central Tetrahedral atom = Triangular pyramid shape

                          P-H bond (2.1-2.1) is nonpolar = all nonpolar bonds = Nonpolar molecular polarity

   2.)  HCN        2 Groups of electrons around C = Linear Electron Geometry

                          Linear Electron Geometry = sp Hybridization of C

                          2 atoms around central Linear atom = Linear shape

                          CH bond (2.5-2.1) is nonpolar

                          C≡N bond (3.0-2.5) is polar = at least one polar bonds = Polar molecular polarity

• Question 5

  Rank the following materials from highest BP to lowest BP

  N₂, NaF, NH₃, Ni, HI

  Correct Answer

  HIGHEST BP TO LOWEST BP

  Highest BP: Ni = NaF (metallic, ionic)

  NH₃ (H-bonding)

  HI (polar)

  Lowest BP: N₂ (nonpolar)

• Question 6

  Explain whether the following material is ionic, polar or non-polar. Describe whether it is soluble or insoluble in water?

  HCl

  Correct Answer

  HCl                 One polar bond (H-Cl) = Polar

                         Water soluble since like dissolves like and water is polar

• Question 7

  For the two compounds given below, one compound obeys the rules of covalent bonding fulfilling the octet rule. The other compound does not obey these rules. Using your knowledge of the periodic table and Lewis Structures, state which compound is correct and which compound is not correct. Your answer must also provide an explanation. (Hint: There are no double bonds involved in these compounds.)

  OF₂ and OF₃

  Correct Answer

  OF₂ is correct and OF₃ is not correct. Oxygen has 6 valence electrons and is capable of forming two single bonds, but not three.