The maximum number of hydrogen bonds that can form between H₂N – NH₂ (hydrazine) and water is

(1) 2
(2) 1
(3) 3
(4) 4

Hydrogen Bonding Between Hydrazine and Water

A crucial element of molecular interactions is hydrogen bonding, especially in molecules like hydrazine (H₂N-NH₂) that dissolve in water. Because hydrazine contains two -NH₂ (amine) groups, it can form multiple hydrogen bonds.

How Do Hydrazine and Water Create Hydrogen Bonds?

There are two ways that hydrazine can create hydrogen bonds:

As a Donor of Hydrogen Bonds: The oxygen in water molecules can receive hydrogen bonds from the hydrogen atoms in -NH₂ groups.

As a Hydrogen Bond Acceptor: The nitrogen atoms in -NH₂ groups have lone pairs that allow them to take up hydrogen bonds from water molecules.

Hydrazine and Water’s Maximum Hydrogen Bonds

Two hydrogen bonds can be formed by each -NH₂ group, one as a donor and one as an acceptor. Since hydrazine has two -NH₂ groups, it can form up to four (4) hydrogen bonds with water.

Examination of the Potential for Hydrogen Bonding:

The hydrazine hydrogen atoms donate two hydrogen bonds to the water’s oxygen.

The nitrogen atoms in hydrazine form two hydrogen bonds with water.

Response: Option 4 is the right one.

Out of all the possibilities, Option 4 allows hydrazine to form the most hydrogen bonds with water. Hydrazine is highly soluble in water and more reactive in water solutions due to its high hydrogen bonding ability.