shapes of molecules

Question 1

shape

Answer 1

• influence chemical/physical properties
• reactivity
• melting points
• enzyme/protein

Question 2

VSEPR

Answer 2

valence shell electron pair repulsion

Question 3

VSEPR theory

Answer 3

• lowest energy state to be stable
• electron groups around central atom of molecule
• have bonding pairs and lone pairs

Question 4

shape theory

Answer 4

• electrons are negatively charged, valence shell electrons want to be as far apart as possible’-constraints of needing to be bonded and trying to be distance allows geometry prediction
• knowing geometry allows shapes/bond angles of molecules prediction

Question 5

co ordination number

Answer 5

number of bonded atoms

Question 6

steric number (SN)

Answer 6

number of atoms bonded to central atom + number of lone pairs on central atom

Question 7

molecule geometry MG

Answer 7

3D arrangement of atoms in molecules

Question 8

electron geometry EG

Answer 8

3D arrangement of bonding electron pairs and lone pairs around central atom

Question 9

bonding angle

Answer 9

angle between bonds

Question 10

how to find shape of molecule
(pictures in lecture 4 chemistry)
25ish minutes into video lecture 4 chemistry

Answer 10

• draw LDS
• count electron groups, find bond pairs and lone pairs
• decide electron pair geometry (like linear)
• put in positions of other atomic nuclei around central atom
• determine molecule geometry

Question 11

dipole

Answer 11

2 poles

Question 12

S+ and s-

Answer 12

S+ electron poor

S- electron rich

Question 13

identical polar bonds in symmetry and identical polar bonds but not symmetrically opposite

Answer 13

symmetry:
-dipoles cancels out 
-molecule is non-polar
-carbon dioxide 
nonsymmetric:
-dipoles do not cancel out 
-molecule is polar 
-water