Question

Why do we get dew on the surface of a cold soft drink bottle kept in the open air?

Answer 1

Hint: Condensation of water vapor is the reason behind this. Air surrounding the bottle has a higher temperature than the soft drink bottle. We know that heat flows from the hot body to a cold body. Here, the surrounding air and the cold bottle have different temperatures; as result heat transfers from one body to the other.

Complete step-by-step solution:
We get dew on the surface of a cold soft drink bottle kept in the air due to condensation. Condensation is the process due to which water vapor in the air is converted into liquid water. It is the opposite of evaporation of water. Condensation occurs in two ways: either the air is cooled to its dew point or it becomes so saturated with water vapor so that it cannot hold any more water. The temperature at which condensation happens is known as the dew point. When water changes between vapor, liquid, and solid, the arrangement of water molecules changes. Water molecules in the vapor are arranged more randomly than in liquid water. Therefore, during the condensation and the water evaporation, the water molecules become more organized and heat is released into the atmosphere. Due to the condensation of water vapor, water droplets are produced on the surface of cold soft drink bottles. Here, the temperature of the surrounding air is higher than the temperature of the cold soft drink. A cold surface reaches its dew point when warm air hits the surface. Heat is released into the atmosphere and vapor condenses. This leaves droplets of water on the surface of the bottle.

Note: Condensation is an important process in the water cycle because it is responsible for the formation of the clouds. When the droplets or ice crystals within clouds grow in size, they become too heavy to stay in the air, falling to the ground as rain, snow, and other types of precipitation, which is the primary route for water to return to the Earth's within the water cycle.