How many lone pairs of electrons are present in the Lewis dot structure of hydrazine (N2H4)?

• A. 0
• B. 1
• C. 2
• D. 4

Answer: (C)

Verified step by step guidance

1. Step 1: Determine the total number of valence electrons in hydrazine (N2H4). Nitrogen (N) has 5 valence electrons and hydrogen (H) has 1 valence electron. Calculate the total by multiplying the number of each atom by its valence electrons and summing them up: \$2 \times 5 + 4 \times 1$.
2. Step 2: Draw the skeletal structure of hydrazine, connecting the two nitrogen atoms with a single bond and attaching the four hydrogen atoms to the nitrogens (two hydrogens per nitrogen).
3. Step 3: Distribute electrons to satisfy the octet rule for each nitrogen atom. Each bond (N-H or N-N) represents 2 shared electrons. Subtract the bonding electrons from the total valence electrons to find the remaining electrons to be placed as lone pairs.
4. Step 4: Assign the remaining electrons as lone pairs on the nitrogen atoms. Since hydrogen atoms only form one bond and do not have lone pairs, all lone pairs will be on the nitrogen atoms.
5. Step 5: Count the lone pairs on the nitrogen atoms. Each lone pair consists of 2 electrons. The total number of lone pairs on both nitrogen atoms combined is the answer.