College

Water and ammonia interact to form hydrogen bonds, as represented in the figure. Which statement best helps explain the formation of the hydrogen bond represented in the figure?

A. The oxygen has a partial positive charge, and the nitrogen has a partial negative charge.
B. The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.
C. The hydrogen attached to the oxygen has a partial negative charge, and the nitrogen also has a partial negative charge.
D. The nitrogen has a partial positive charge, and the hydrogen attached to the oxygen also has a partial positive charge.

Answer :

The correct answer is option B)The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.

The formation of hydrogen bonds between water and ammonia is governed by the electronegativity difference between the atoms involved. Hydrogen bonds occur when a hydrogen atom is covalently bonded to a highly electronegative atom and is attracted to another electronegative atom. In this case, the electronegative oxygen in water and the electronegative nitrogen in ammonia are the key players.

Option B best explains the formation of the hydrogen bond. In water, oxygen is more electronegative than hydrogen, creating a partial negative charge on the oxygen and a partial positive charge on the hydrogen. In ammonia, nitrogen is more electronegative than hydrogen, resulting in a partial negative charge on nitrogen and a partial positive charge on the hydrogen attached to it. The partial positive charge on the hydrogen in water is attracted to the partial negative charge on the nitrogen in ammonia, forming a hydrogen bond.

Option B captures the correct polarities of the atoms involved, illustrating the basis for hydrogen bond formation between water and ammonia.