#4429. Sweet Chemistry

Science, level: Senior
Posted Tue Jul 27 16:55:24 PDT 2010 by Jessica Jones (Jessica Jones).
Alamo, USA
Materials Required: gum drops, toothpicks
Activity Time: one class period
Concepts Taught: VSEPR, Octet Rule, Bonding

Review concepts like the octet rule, valence shell electron pair repulsion, and covalent bonding before beginning the activity.

Sweet, Chemistry!

Name_______________________________ Date___________________

Build the following molecules in your group with the toothpicks and "atoms". Keep in mind the valence shell electron pair repulsion (VSEPR) model which will determine the angles formed by the bonds. Remember the Octet Rule and look at the Periodic Table to decide how many bonds each atom will make.

After building the molecule models answer the questions at the bottom of the page.

H2O

BF3

CO2

H2 O2

C2 H6

NH3

C2H4

C2H6O -- Make two different molecules with this same formula.

C3 H8O -- Try to make three different molecules with this same formula.

1. Which molecule had a linear arrangement (a 180 degree bond angle)?

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2. Which molecule had a trigonal planar shape (a flat triangle)?

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3. Which molecule had a trigonal pyramidal shape (triangular pyramid)?

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4. What are different molecules with the same chemical formula called?

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5. What two molecules had double bonds?

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