Lewis Structures and Valence Electrons

The video tutorial explains the Lewis structure of the cyanate ion (OCN-), detailing the distribution of 16 valence electrons among carbon, oxygen, and nitrogen. It discusses the placement of atoms, initial bonding, and the need to share electrons to satisfy the octet rule for carbon. The tutorial also covers calculating formal charges and evaluates alternative structures, concluding with the most stable configuration where the negative charge resides on the most electronegative atom, oxygen.

What is the total number of valence electrons in the cyanate ion?

• 18

• 16

• 20

• 14

Which atom is placed at the center of the cyanate ion's Lewis structure?

• Hydrogen

• Oxygen

• Nitrogen

• Carbon

Why is nitrogen chosen to share electrons with carbon instead of oxygen?

• Nitrogen is less electronegative than oxygen.

• Nitrogen is closer to carbon in the periodic table.

• Nitrogen has more valence electrons than oxygen.

• Nitrogen is more electronegative than oxygen.

How many electrons does carbon have after forming a double bond with nitrogen?

• 10

• 8

• 6

• 4

What is the formal charge on oxygen in the OCN- Lewis structure?

• -1

• +1

• 0

• -2

What would be the formal charge on nitrogen if a double bond was formed between oxygen and carbon?

• 0

• -2

• -1

• +1

Why is the negative charge placed on oxygen in the best Lewis structure for OCN-?

• Oxygen has the most valence electrons.

• Oxygen is the most electronegative atom.

• Oxygen is the least electronegative atom.

• Oxygen is in the center of the structure.