Molecular Geometry and AXE Notation

The video explains the molecular geometry and bond angles of the NH2- ion. It starts with the Lewis structure, showing two hydrogen atoms and two lone pairs on the nitrogen, resulting in a bent molecular geometry. The ideal bond angle is 109.5 degrees, but due to lone pair repulsion, it is closer to 105 degrees. A 3D visualization demonstrates how lone pairs affect the geometry. The video concludes with an explanation of the AXE notation, identifying NH2- as AX2E2, confirming its bent geometry.

What is the steric number of NH2- based on its Lewis structure?

• 2

• 5

• 3

• 4

What type of molecular geometry does NH2- exhibit?

• Tetrahedral

• Bent

• Trigonal planar

• Linear

What is the ideal bond angle for a bent molecular geometry?

• 90 degrees

• 109.5 degrees

• 120 degrees

• 180 degrees

How do lone pairs affect the bond angle in NH2-?

• They have no effect on the bond angle.

• They increase the bond angle.

• They make the bond angle exactly 109.5 degrees.

• They decrease the bond angle.

What is the approximate bond angle in NH2- due to lone pair repulsion?

• 120 degrees

• 180 degrees

• 105 degrees

• 90 degrees

What is the electron geometry of NH2-?

• Linear

• Trigonal planar

• Octahedral

• Tetrahedral

In AXE notation, what does 'A' represent for NH2-?

• The total number of bonds

• The number of lone pairs

• The number of atoms attached

• The central atom

In AXE notation, what does 'X' represent for NH2-?

• The total number of bonds

• The number of atoms attached

• The central atom

• The number of lone pairs

In AXE notation, what does 'E' represent for NH2-?

• The number of lone pairs

• The total number of bonds

• The central atom

• The number of atoms attached

What is the AXE notation for NH2-?

• AX2E

• AX2E2

• AX3E

• AX3E2