Needed done ASAP.
Lab: Phet Molecular Shapes VSEPR Activity
Log on to
https://phet.colorado.edu/en/simulation/molecule-shapes
either by Googling “phet simulations molecule shape.” Click on the play button in the center.
Introduction
Atoms bond to satisfy their need for more electrons. If both atoms have high electronegativities (are nonmetals), atoms will share electrons to satisfy the Octet Rule – every atom wants 8 electrons to fill the s and p orbitals in the outer energy level. But, as you will see, if the electronegativities are high enough and both atoms unwilling to give up electrons, sometimes atoms can deviate from and not follow the Octet Rule.
Because electrons have a negative charge and atoms occupy space, bonds and electrons will spread out as much as possible. Since we write in a two dimensional plane on paper, it is difficult to visualize the true geometry of these molecules. This activity and the program you are about to use allows us to visualize on a more 3-dimensional scale.
Part 1 – Generic
Molecule
s
Fill in the chart below by creating the generic molecules below. On your screen in the lower left corner, click on “
molecule geometry
.” Add atoms and electron pairs as needed to produce the generic formula. Once the molecule is assembled, click and drag the screen to spin the atom around. Click on the “
Show bond angles
.” Use the following key:
·
A
– central purple atom – cannot be removed
·
B
– single bonded white atom
·
C
– double bonded white atom
·
D
– triple bonded white atom
·
E
– Electron pairs not bonded (lone pair)
In each box:
1. Take a screenshot from your computer and place it into the box
2. Identify which molecule from the HW yesterday corresponds to the box
3. Write the Molecular Geometry (MG)
4. Look at the central atom, is its octet satisfied?
Molecule | |||
AC2
Molecule from HW: MG ___________________________ Octet? ______ |
ABE3 Molecule from HW: MG _____________________________ Octet? ______ |
AB3E Molecule from HW: |
AB Molecule from HW: |
ACE2 Molecule from HW: |
AB2E2 Molecule from HW: |
AB2C Molecule from HW: |
ABD Molecule from HW: |
AB4 Molecule from HW: MG _____________________________ Octet? _____ |
ADE Molecule from HW: |
Part 2 – Octet Rule Breakers
While still in the “Real Molecules” tab, select the following molecules. Take a screenshot from your computer and place it into the box, write the molecular geometry, and write how many electrons are on the central atom.
SO2 MG _____________________________ Electrons?____ |
XeF2 MG _____________________________ Electrons?____ |
ClF3 MG _____________________________ Electrons?____ |
SF4 MG _____________________________ Electrons?____ |
XeF4 MG _____________________________ Electrons?____ |
BrF5 MG _____________________________ Electrons?____ |
PCl5 MG _____________________________ Electrons?____ |
SF6 MG _____________________________ Electrons?____ |
Post Lab Questions
1. The program did not give a bond
angle
to a molecule consisting of only two atoms. Why? Think geometry class.
2. What happens to the bond angle within a molecule as you add more bonds to the central atom?
3. How does a lone pair affect the molecular geometry of a molecule?
4. Explain how the “octet rule breakers” violate the octet rule? Did all of these “octet rule breakers” violate the octet rule the same way?
5. Did the molecular geometry of the “octet rule breakers” match any that did follow the octet rule? If so which ones and why?