Mpemba Competition Submission of the Day

Chris Waltzek

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Mpemba Effect - Solved
Chris Gilbert Waltzek
Northcentral University



Abstract

This brief paper proposes a startling and unique solution to the question asked by The Royal Society of Chemistry: “Why does hot water freeze faster than cold water.” The Mpemba Effect still baffles scientists several hundred years after Roger Bacon posed the question to colleagues. During the course of this investigation, the empirical results indicate that hot water does not, in fact freeze at a faster pace than does cold water. A simple control is imposed on both the hot and cold bodies of water. Boiling water and cold water are each poured into two separate airtight containers, without any remaining airspaces, the results are reversed.

Mpemba Effect - Deciphered

In 1968, a Tanzanian student Erasto Mpemba posed visiting professors an ancient problem that has eluded great thinkers for centuries: “Why does hot water freeze faster than cold water.” In fact Roger Bacon reportedly used the conundrum to argue for the scientific method (Bacon, 1733). The question which still stymies scientists to this day earned the moniker, The Mpemba Effect. The Royal Society of Chemistry rehashed the investigation by offering the public a generous prize for the solution. This brief paper proposes a startlingly simple solution to The Mpemba Effect, riddle.

Findings

During the course of this investigation, the empirical results indicate that hot water does not, in fact freeze at a faster pace than does cold water. The Mpemba Effect appears to be the result of dissolved hot water molecules changing states into water vapor, in the process releasing large amounts of heat, lowering dissolved gas levels while lowering the freezing point. Whereas cool water evaporates more slowly, retains a higher relative proportion of dissolved gases, a lower freezing point and thus freezes more slowly.

However, in order to adequately answer the question posed by President Professor David Phillips at The Royal Society of Chemistry: “Why does hot water freeze faster than cold water,” a simple control is imposed on both the hot and cold bodies of water. For instance, when boiling water and cold water are each poured into two separate airtight containers, without any remaining airspaces, the results are reversed.

Discussion

By sealing both the hot and cold water in airtight containers, no gases escape. Since water vapor is no longer released from the containers, the hot water cools at a far slower pace. In fact, in every test conducted, regardless of the container type used, the results were identical: cold water freezes more rapidly than does hot water. Thus it appears that the riddle has been solved. The reason why cold water freezes more quickly than hot water is that hot water does not develop an ice cap (insulation) as quickly as cold water, allowing water vapor to escape, removing relatively more heat from the hot water.




References

Roger, Bacon. (1733). Opus Majus. London, England. Retrieved from http://www.archive.org/details/opusmajusofroger002065mbp

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