Name: _______________ Date: _____________ SCH3U- Bonding Chapter Review KCI 2016 KEY1. What is an ionic bond? 2. What is a covalent bond? What types of element tend to form covalent bonds?a bond in which e- are transferred from themetal to the non-metal

A bond in which e- are shared b/t two non-metals; non-metals

3. Show how atoms of aluminum and sulfur would react to form a compound. Include all necessary energy terms.

4. List the steps required in determining the structural formula of SeO2

Step1: find total # valence e-= 6x 2+ 6 =18e-Step 2: select the central atom (one with the highest bonding capacity, usually one with lower electronegativity; never H) so Se

Step 3: distribute 18e- around the surrounding atoms in a way that they all achieve an octet (2 for H)

Step 4: Any remaining e- is to be put on the central atom Step 5: move e- from surrounding atoms if the central atom hasn’t attained octetStep 6: for compounds with many possible Lewis structure, evaluate the most stable structure using formal charges5. a. Which molecule exhibit 0% ionic character? Give an example and justify with E.N.

diatomic moleculee.g. N2

E.N.=0 0% ionic character

b. Determine % ionic character and classify the type of bonding for:i. AlCl3

E.N. Al-Cl bond = 3.0-1.5 = 1.50% ionic = 43It is an ionic bond although E.N. is <1.7 (goes to show bonding continuum is not the only tool to ground our prediction)

ii. BF3

E.N. B-F bond = 4.0-2.0 = 2.0% ionic = 63It is NOT an ionic bond although E.N. is >1.7 (goes to show bonding continuum is not perfect)

c. Using E.N. to determine which of the following pairs would exhibit the GREATER ionic character?

i. CH4 or COE.N. C-H bond = 2.5-2.1 =0.4

E.N. C-O bond = 3.5-2.5 = 1 greater ionic character (i.e. 22%)

ii. SO2 and NO2

E.N. S-O bond = 3.5-2.5 = 1 greater ionic character also 22%E.N. N-O bond =3.5-3.0 =0.5

6. Define bonding e pairs and lone pairs? How are they different?Bonding e pairs involve in a bondsLone pairs are non-bonding e-

Difference: lone pairs are not shared b/t 2 non-metals and tend to compress the bond angle, making them narrower than they’re supposed to be

7. Draw the Lewis structures for the following compounds. All elements obey their bonding capacity.Show bond dipoles on Structural formula when determining polarity of the molecule

Molecule Lewis dot structure Structural formula # bonding e pairs

# of lone pairs

Polarity(Polar/Non)

CO2 4 4 Non-polar (no net dipole)

H2 H-H 1 0 Non-polar

CHCl3 4 9 polar

PH3 3 1 Non-polar as P-H bond is pure covalent bond (E.N. =0)

NSF 3 6 polar

COCl2 4 8 polar

C2H3Br 6 3 polar

8. These following molecules are shown in their actual 3D shape. Which one is polar? Display bond dipoles and molecular dipole for both molecules if necessary:

a. Polar

b. non- polar

9. In your own word, what do you understand by the term “dipole”? Give an example.Your turn 10. Why do some molecules require 3D diagrams while others do not?Due to the presence of lone pairs, bonds will be compressed at an angle that is not viewable with 2D drawing. 3D diagrams or model helps identify the dipoles that aren’t cancelled out as a result of this compression of bond angle caused by the lone pairs

11. What make metals good conductors of electricity? Explain.They have e- that are mobile and this allows electricity to move through the body of the metal. Having moveable charges is the requirement for conducting electricity.