Final answer:
Condensation on the outside of a glass of iced tea occurs when the surrounding air is cooled below the dew point by the cold glass, causing water vapor to change into liquid water and release energy that speeds up the melting of ice.
Step-by-step explanation:
On a hot summer day, the phenomenon of condensation is observed when water vapor in the air comes in contact with a cold surface, such as the outside of a glass of iced tea. Due to the lower temperature of the glass, the warmth of the surrounding air is reduced to below the dew point, meaning the air is no longer able to retain as much water vapor at that cooler temperature. As a result, the water vapor condenses into water droplets.
When this condensation occurs, energy is released in the process, which then contributes to speeding up the melting of the ice inside the glass. This release of energy is a consequence of the exothermic nature of the phase change from gas to liquid. The increased rate of melting is essential to understand when considering the physical changes taking place in the iced tea mixture, which consists of sugar, tea, lemon, and water.