As temperature increases in water, there is increased evaporation. Which of the following BEST explains why this happens?
A: Covalent bonds form
B: Surface tension decreases
C: Hydrogen bonds tighten
D: Heat capacity lowers
C: Hydrogen bonds tighten
Explanation: As temperature increases in water, the kinetic energy of the water molecules also increases. This increased kinetic energy leads to more frequent collisions among the water molecules, which causes the hydrogen bonds between them to break and reform more frequently. When the temperature is high, the hydrogen bonds tighten less frequently, and more water molecules gain enough energy to break free from the liquid and become vapor, leading to increased evaporation.
The correct answer is D: Heat capacity lowers.
Explanation:
When temperature increases in water, there is increased evaporation, which means more water molecules transition from the liquid phase to the gas phase. This occurs because as temperature rises, the kinetic energy of water molecules also increases, leading to greater movement and higher chances for individual water molecules to overcome the attractive forces holding them together in the liquid phase.
Heat capacity refers to the amount of heat energy needed to raise the temperature of a substance. Water has a relatively high heat capacity, which means it can absorb and store a considerable amount of heat energy before its temperature changes significantly. This is due to the extensive hydrogen bonding between water molecules, which creates strong attractions and resists changes in temperature.
As the temperature increases, water molecules gain more energy and motion. This increased movement weakens the hydrogen bonds between them, allowing individual water molecules at the surface to break away from the liquid phase and escape as gas molecules (water vapor). This process is known as evaporation.
Therefore, when the heat capacity of water lowers with increasing temperature, it means that water molecules require less energy to break free from the liquid phase and evaporate. Hence, the correct answer is D: Heat capacity lowers.
The correct answer is C: Hydrogen bonds tighten.
Explanation:
When the temperature of water increases, the kinetic energy of water molecules also increases. This leads to an increase in the movement and vibration of the molecules. As a result, the hydrogen bonds between water molecules weaken and become less stable.
The weakening of hydrogen bonds allows water molecules to break free from each other and escape into the atmosphere as vapor through the process of evaporation. Therefore, as the temperature increases, the hydrogen bonds between water molecules tighten, leading to increased evaporation.