Context-

• The Mpemba Effect, named after Tanzanian student Erasto Mpemba (1969), fascinated scientists.
• Aristotle, Bacon, and Descartes observed this paradoxical phenomenon centuries prior.

Phenomenon:

• Counterintuitive Finding: Hot water freezes faster than cold water in similar conditions.

Key Experiments:

• Microbubbles' Role: Microbubbles persist in heated water post-boiling, fostering convection and facilitating faster heat transfer during cooling.
• Evaporation Dynamics: Warmer water, evaporating more, expedites heat loss (evaporation being inherently endothermic, akin to how sweat cools the skin).
• Density Impact: Warmer water, being less dense, enhances both convection and accelerated heat transfer.

• Exploring Precipitation: Scientists investigate if compounds like calcium carbonate, precipitated by boiling, dissolve and elevate the water's freezing point.