CK-12-Chemistry Intermediate

8.2. Ionic Bonds and Ionic Compounds http://www.ck12.org

a. S

b. S^2 −

c. Cs

d. Cs+

e. P

f. P^3 −

g. Sn

h. Sn^2 +

2. Which of the following pairs of atoms would be expected to combine chemically to form an ionic compound?
   Explain.
   a. Li and O
   b. N and H
   c. Al and S
   d. Cl and F
   e. Sr and Br
   f. Zn and I


3. Explain why most ionic compounds are strong and hard, yet brittle.


4. Explain why potassium fluoride does not conduct an electric current as a solid, but it does conduct after being
   dissolved in water.

Problems

5. Use electron dot diagrams to demonstrate the formation of ionic compounds involving the following elements.
   Use arrows to show the transfer of electron(s) from one atom to another.
   a. K and O
   b. Ca and N
   c. Ba and S


6. Write the formula units for each of the ionic compounds from question number 5.


7. Answer the following:
   a. What is a coordination number?
   b. If the coordination numbers for each of the two ions in a crystal lattice are identical, what must be true
   about the formula unit of the compound?
   c. An ionic compound forms between metal A and nonmetal B. The coordination number of the cation of
   element A is 4 and the coordination number of the anion of element B is 8. Write the chemical formula
   of the compound.


8. A general ionic bond forms between a cation X+and an anion Y−. How will the strength of the ionic bond
   change if the following changes are made? In other words, will the resulting bond be stronger or weaker?
   a. The charge of the cation is doubled.
   b. The size of the cation is increased.

Further Reading / Supplemental Links

• IonicBond (http://en.wikipedia.org/wiki/Ionic_bond


• Bonding (http://www.chemteam.info/Bonding/Bonding.html


• Claude H. Yoder,Ionic Compounds: Applications of Chemistry to Mineralogy. Wiley-Interscience, 2006.