Molecular Geometry of CH3-

The video tutorial explains the molecular geometry of the methyl anion (CH3-). It begins with constructing a valid Lewis structure, followed by determining the steric number, which is four due to three hydrogen atoms and one lone pair bonded to the central carbon atom. This results in a trigonal pyramidal geometry with a bond angle slightly less than 109.5 degrees due to the repulsion from the lone pair. The video also visualizes the geometry and explains the use of AXE notation to confirm the molecular shape.

What is the first step in determining the molecular geometry of CH3-?

• Measuring bond angles

• Drawing a valid Lewis structure

• Counting the number of atoms

• Identifying the central atom

What is the steric number of CH3-?

• 3

• 4

• 5

• 6

Which molecular geometry is associated with a steric number of 4 and one lone pair?

• Trigonal planar

• Tetrahedral

• Trigonal pyramidal

• Linear

How does the lone pair affect the bond angles in CH3-?

• It makes the bond angles exactly 109.5 degrees

• It has no effect on the bond angles

• It decreases the bond angles

• It increases the bond angles

What is the ideal bond angle for a trigonal pyramidal geometry?

• 109.5 degrees

• 120 degrees

• 90 degrees

• 180 degrees

In the visualization of CH3-, what color represents the central carbon atom?

• Purple

• Green

• Blue

• Red

What is the effect of the lone pair on the molecular geometry of CH3-?

• It makes the geometry linear

• It has no effect on the geometry

• It changes the geometry to trigonal planar

• It results in a trigonal pyramidal geometry

What does 'A' represent in the AXE notation for CH3-?

• The number of bonded atoms

• The central atom

• The number of lone pairs

• The type of bonds

How many hydrogen atoms are bonded to the central carbon in CH3-?

• 2

• 3

• 1

• 4

What is the AXE notation for CH3-?

• AX4

• AX3E

• AX3

• AX2E2