U5L11 DE EQ - Wed Mar 4 - 8.5 Drawing Lewis Structures pt 2

Formal charge is best described as:

• The actual electric charge on an atom in a molecule

• The charge an atom would have if bonding electrons were shared equally between atoms

• The number of valence electrons an atom has lost

• The electronegativity of an atom in a bond

Which of the following statements about formal charge is TRUE?

• Formal charges represent the actual charges on atoms

• Formal charges are a bookkeeping tool and do not represent real charges on atoms

• Formal charges are determined by electronegativity differences

• The formal charges in a molecule do not need to add up to the overall charge

Use the Lewis structure for NH₃ shown below. What is the formal charge on the nitrogen atom?

• +1

• 0

• -1

• +2

Use the Lewis structure for H₃O⁺ shown below. What is the formal charge on the oxygen atom?

• 0

• +1

• -1

• +2

Two valid Lewis structures for CS2 are shown with their formal charges. Which is the dominant structure?

• Structure I, because all atoms have formal charges of zero

• Structure II, because the triple bond is stronger

• Structure II, because it places a negative charge on sulfur

• Both structures are equally dominant

Two valid Lewis structures for OCS are shown with their formal charges. Which is the dominant structure?

• Structure II, because it has a triple bond

• Structure I, because all formal charges are zero

• Structure II, because the negative charge is on sulfur

• Both are equally dominant

Tags

NGSS.HS-PS1-2

Two valid Lewis structures for SCN⁻ are shown with their formal charges. Which is the dominant structure?

• Structure I, because the negative charge is on sulfur

• Structure II, because the negative formal charge is on nitrogen, which is more electronegative than sulfur

• Structure I, because single bonds are preferred

• Both are equally dominant

Two valid Lewis structures for NCO⁻ are shown with their formal charges. Which is the dominant structure?

• Structure I, because the negative formal charge is on oxygen, which is more electronegative than nitrogen

• Structure II, because the negative charge is on nitrogen

• Structure I, because triple bonds are always preferred

• Both are equally dominant

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-1