Formal Charge and Lewis Structure of NO3-

The video tutorial explains the process of drawing the Lewis structure for the nitrate ion (NO3-). It begins by calculating the total valence electrons, placing nitrogen in the center due to its lower electronegativity, and arranging the oxygen atoms around it. Initial bonds are formed, and adjustments are made to fulfill the octet rule by creating a double bond between nitrogen and one oxygen. The formal charges are calculated, showing a +1 charge on nitrogen and -1 on the singly bonded oxygens, resulting in an overall -1 charge for the ion. The structure is enclosed in brackets to indicate its ionic nature.

How many valence electrons does nitrogen contribute to the NO3- ion?

• 6

• 8

• 3

• 5

What is the total number of valence electrons in the NO3- ion?

• 18

• 20

• 24

• 26

Where is nitrogen placed in the NO3- Lewis structure?

• On the outside

• In the center

• Between two oxygens

• Above the oxygens

What adjustment is made to ensure nitrogen fulfills the octet rule?

• Forming a double bond with one oxygen

• Adding a fourth oxygen atom

• Removing electrons from oxygen

• Adding more electrons to nitrogen

What is the formal charge on the nitrogen atom in the NO3- ion?

• -1

• 0

• +1

• +2

What is the formal charge on the oxygen atom with a double bond in the NO3- ion?

• 0

• -1

• +1

• +2

Why are brackets used in the final NO3- Lewis structure?

• To separate the atoms

• To highlight the central atom

• To show it is an ion with a negative charge

• To indicate it is a molecule