Molecular Geometry and Lewis Structures

The video tutorial explains how to draw the Lewis structure for the nitrite ion (NO2-). It begins by counting the total number of valence electrons, considering the periodic table groups for nitrogen and oxygen. The tutorial then guides through placing the least electronegative atom, nitrogen, in the center and forming bonds with oxygen atoms. It addresses completing octets and forming double bonds to satisfy the octet rule. The concept of resonance is introduced, showing how the double bond can be averaged across the ion. Finally, the molecular geometry is discussed, highlighting the bent shape due to lone pair repulsion, and the bond angle is specified as 115 degrees.

How many total valence electrons are present in the NO2- ion?

• 18

• 17

• 16

• 19

Which atom is placed at the center of the NO2- Lewis structure?

• Carbon

• Nitrogen

• Hydrogen

• Oxygen

What is the purpose of placing a pair of electrons between atoms in a Lewis structure?

• To complete the atom's octet

• To increase the atom's charge

• To form a chemical bond

• To create a lone pair

How many valence electrons are used after completing the octets for the outer atoms in NO2-?

• 16

• 18

• 20

• 14

What adjustment is made when the central nitrogen atom in NO2- lacks a complete octet?

• Add more electrons

• Form a double bond

• Remove an electron

• Change the central atom

Why are brackets used around the NO2- Lewis structure?

• To indicate resonance

• To denote a double bond

• To show it is an ion

• To highlight the central atom

What does resonance in the NO2- ion imply?

• The ion has no double bonds

• The double bond is averaged across the ion

• The double bond is localized

• The ion has a fixed structure

What is the molecular geometry of the NO2- ion?

• Linear

• Bent

• Trigonal planar

• Tetrahedral

What causes the bent shape in the NO2- ion's molecular geometry?

• The presence of a double bond

• The lone pair on nitrogen

• The electronegativity of oxygen

• The ion's negative charge

What is the bond angle in the NO2- ion?

• 115 degrees

• 120 degrees

• 90 degrees

• 104.5 degrees