Chm 211 Exam 6      Name__________________________

 

 1-3 Short answers

.a) Put in the formal charges on a  molecule of ozone, O3,  that has the electronic structure best represented by (one pairs not included):


        O--O=O


b) What is the most electronegative element?


c) How many unpaired electrons are there in one atom of     oxygen (in its ground state configuration)? How do you know?



d). What element has the smallest atomic radius? Explain?



e) Which of the second period elements (Na to Ar) has the highest ionization potential? Explain why




.f) The family of elements with the electron configuration     [noble gas] ns1  is what family?



g) How many moles are there in 1.2 g of CO2?



h)  What  would  you expect for the formula of a  ionic  compound formed from Al and S.



i) How many valence electrons are their in a NO3-   anion?  Show your arithmetic.



j) Put in the lone pair electrons on the carbon dioxide molecule that has the Lewis structure



    O=C=O



 

4.  Write the electron configuration, box diagrams with inert gas abbreviations, for Ni and Ni+2?  Show how many unpaired electrons would  be  in  the ground state of each?  















5.   Write the Lewis structures for the following (include      lone pair electrons)     

a) HCN skeleton is


    H-C-N  


b) C2H2  skeleton is


    H-C-C-H     


c)  NO3-1 skeleton is  


    O-N-O
         |
        O
    

 6.  The benzene compound, C6H6,  consists of molecules that have 6 C atoms in a ring with each C atom attached to 1 H atom.  Draw the Lewis structures of the two resonance structures of benzene.





















7. a) Fill in the multiple bonding in the following structure. Put lone pair electrons in the structure and indicate any formal charges.


    H-N-N-N





 b)  Write the electronic structure of the  compound, SO2..  The skeleton consists of a center S bonded to two different  oxygen atoms.  Put lone pair electrons in the structure and indicate any formal charges.















8.  Describe the bonding in Na2CO3 in detail.











9.  Describe how  ionic compounds differ from  covalent compounds in the following ways.  Be specific so you might start you answers like: Covalent compounds ______ while ionic compounds  ________.

a) the conductivity of aqueous solutions.









b) their physical states.










c) their composition. ie how they are composed in terms of metallic and non-metallic elements.