Study Guide: Unit 4
1. Define the following:
a. Ionic Bond – the complete transfer of electrons from one element to another.
b. Covalent Bond -the Sharing of electrons between two elements.
c. Metallic Bond -the attraction of a nucleus and surrounding electrons, forms a sea of
electrons.
d. Polar –the unequal distribution of electrons.
e. Nonpolar –The equal distribution of electrons.
f. Lewis Structure – combining of lewis dot structures to predict the shape, and properties
of molecules.
g. Valence Electron –electrons in the highest energy level that are available for bonding.
2. Determine the bond types in the following compounds, distinguish between polar and
nonpolar bonds for covalent
molecules:
a. MgF2 - Ionic
b. O2- nonpolar
c. H2O- polar
d. CoNi- metallic
e. CH4- Polar
f. NH3- Polar
g. CaMn- Metallic
h. CO2- Polar
3. Draw the Lewis structures for the following: Look these up online.
a. BeI2 –Salt
b. SF2–Bent, polar, Dipole
c. CaS–Salt
d. CF2Cl2–Tetrahedral, polar, dipole
e. CH2O–Trigonal planar, polar, h-bonding
f. N2–Linear, nonpolar, london
g. CO2–Linear, nonpolar, London
h. NF3–Trigonal Pyrimidal, polar, dipole
Study Guide: Unit 4
4. Predict the shape of the compounds listed in number 3.
See above.
5. Predict the polarity of the compounds listed in number 3.
See above
6. (Honors ONLY) Identify the intermolecular forces in the compounds listed in number 3.
See above
7. What are the 5 shapes based on VSEPR theory?
Tetrahedral, Trigonal Planar, Trigonal Pyrimidal, Bent, Linear, Salt
8. Rank the intermolecular forces in terms of increasing strength.
H-Bonding>>>Dipole>>London
9. Rank the following compounds in order of increasing melting point.
NaCl, H2O, CH4, H2S
CH4 < H2S < H2O < NaCl
10. Which of the following would you expect to dissolve in water: MgO, NH3, CO2, KF, CH2O,
CH4, H2S
MgO, NH3, KF, CH2O, H2S
11. What is the difference between a covalent and ionic bond?
Covalent is the sharing of electrons. Ionic is the COMPLETE transfer of electrons
12. Which of the following would conduct electricity given the appropriate conditions:
LiCl, H2O, NH3, CH4, CO2, YCr, ScZr, Fr2O
LiCl, YCr, ScZr, Fr2O
13. When drawing Lewis structures of covalent compounds bonds are shown as what?
Lines
14. Little Jimmie is preforming experiments on an unknown substance. He places a sample
in water to find out that it doesn’t dissolve. What can he conclude from his experiment?
It is either a polar compound OR an Ionic compound
15. Little Jimmie then connects the same substance to an energy source and finds that it
conducts electricity. What type of compound does Little Jimmie have?
An Ionic compound