Homework 4: Chapter 4

1. Which of the following is not a correct Lewis symbol?

a.          b.            c.           d.        

2. The Sulfite ion is,

       a. SO32-    b. NO3 -   c. SO42-        d. CrO4-

3.      The acetate ion is,

        a. CO32-    b. CN -   c. NH4 +    d. C2H3O2-

4.      The correct name for the compound CoCl3 is,

a)  Cobalt chlorate               b) cobalt (III) chloride

c) cobalt (I) chloride           d) cobalt (III) chloride 

5.      Which name/formula combination is wrong?

a) phosphate/PO43-             b) bisulfate/HSO4-

c) sulfurous acid/H2SO3                        d) sodium nitrate/NaNO2

e) dinitrogen tetroxide/ N2O4. 

6.      Which name/formula combination is wrong?

a) phosphorous acid/H3PO3                b) sodium cyanide/NaCN

c) chloric acid/HClO4                            d) calcium hydrogensulfite/Ca(HSO3)2

e) ammonium fluoride/NH4F 

7.      How many valence electrons does a phosphorus atom have?

        a. 3    b. 5    c. 15    d. 18    e. 31

8. The total number of valence electrons in the Lewis formula for PBr3 is

            a.  8    b. 12   c. 18    d. 26  e. 30

9.      The total number of non-bonding-pairs  of electrons in the Lewis formula for NH3 is

a.  0    b.   1     c. 2    d. 3        e. 4

 10. Resonance Lewis structures can be drawn for all the ions and molecules of the following list except,

a.  CO3 2-     b. NO3 -      c. NO2-   d.  CO2

11. Which species of the following list possesses a central atom with more than octet of electrons?

    a.   SO2          b.  PF5       c.  BF3        d.             H2O    e.  NH3

12. The  (H-O) bond in water is best characterized as

a.  polar covalent.                     b.  ionic.

c.  coordinate covalent. d.    pure covalent.

13. Which molecule will not contain a multiple bond?

          a.   N2    b.  CO  c.  SO2  d. F2  e. HCN

14. According to VSEPR theory, what is the molecular geometry of the PF5 molecule?

a.  Square pyramidal   b.  octahedral

c.  tetrahedral                                d. trigonal bipyramidal

e. see-saw  

15.  According to VSEPR theory, what is the molecular geometry of the SF4 molecule?

a. trigonal planar            b. T-shaped

c. tetrahedral                 d. trigonal pyramidal

e. see-saw

16.  Which molecular geometry is matched to CORRECT bond angles?

a. octahedral - 90º and 180º     b. trigonal planar - 90º and 120º

c. tetrahedral - 120º                  d. trigonal bipyramidal- 109.5º

e. linear - 120º

17.  Which of the following is a non-polar molecule?

                         a. CCl4      b. NH3     c. H2S    d. NF3     e. OF2

18. Which of the listed molecules possesses a square planar geometry?

      a. SiCl4             b. SF4           c. XeF4         d. CCl4            e. CH4

 

19.  Which of the following molecules is no polar?

             a. NH3     b. H2S       c. SF6      d.HCl     e. CO

 

 

20.  What is the major type of force that must be  overcome to allow the processes below?

I. the evaporation of propanol (CH3CH2CH2OH)

II. the melting of solid Br2

III. the boiling of liquid BF3

IV. the boiling of liquid CH2Cl2

a. London forces, covalent bonding,  dipole- dipole, dipole-dipole

b. London forces, London forces,  London forces, London forces

c. hydrogen bonding, dipole-dipole, dipole-dipole, London forces

d. hydrogen bonding, London forces, London forces, dipole-dipole

e. dipole-dipole, dipole-dipole,  London forces, London forces