In which phase change are hydrogen bonds formed?(1 point) Responses
A. freezing
B. boiling
C. sublimation
D. evaporation
A. freezing
To determine in which phase change hydrogen bonds are formed, we need to understand what hydrogen bonds are and how they relate to the different phases of matter.
Hydrogen bonds are a type of chemical bond that occurs between a hydrogen atom and an electronegative atom, such as oxygen or nitrogen. These bonds are relatively strong compared to other intermolecular forces, such as van der Waals forces.
Now, let's consider each of the given phase changes:
A. Freezing: Freezing is the phase change from a liquid to a solid. During freezing, the molecules slow down and come closer together, forming a regular crystalline arrangement. While hydrogen bonds can exist in the solid state, they are not typically formed or broken during the freezing process itself.
B. Boiling: Boiling is the phase change from a liquid to a gas. As temperature increases, the molecules gain energy and move more quickly, eventually breaking free from their intermolecular forces and escaping into the gas phase. Hydrogen bonds are generally broken during boiling, as the increased thermal energy disrupts the attractions between hydrogen and electronegative atoms.
C. Sublimation: Sublimation is the phase change from a solid directly to a gas without passing through the liquid phase. This process occurs when the vapor pressure of the solid exceeds the atmospheric pressure. Similar to boiling, hydrogen bonds would generally be broken during sublimation.
D. Evaporation: Evaporation is the phase change from a liquid to a gas at temperatures below the boiling point. Unlike boiling, which occurs throughout the liquid, evaporation happens only at the liquid's surface. During evaporation, the higher-energy molecules near the surface can break free from their intermolecular forces (including hydrogen bonds) and escape into the gas phase.
Considering the explanations above, the correct answer is B. Boiling. During boiling, the increased thermal energy disrupts and breaks hydrogen bonds as the liquid changes to a gas.