Question

The total number of lone-pairs of electrons in melamine is _____

• A. 2
• B. 4
• C. 6
• D. 8

Answer 1

The correct option is C

6

Here, we know the valence electrons of nitrogen = 5.

$\to$ In one bond, one electron is used for bonding.

$\to$ Number of bonds = Number of electrons used for bonding

Now, we will try to place lone pairs on melamine

$\to$ Therefore, there is one lone pair on each N atom because every N atom is making 3 bonds.

$\to$ There is no lone pair on carbon and Hydrogen because all valence electrons are used for bonding.

$\Rightarrow$ Total number of lone pairs = 6