Hot water freezes faster than cold?

  • Thread starter Thread starter Einstein Mcfly
  • Start date Start date
  • Tags Tags
    Cold Hot Water
AI Thread Summary
The discussion centers on the phenomenon where hot water freezes faster than cold water, known as the Mpemba effect. Participants express skepticism about the validity of this effect in closed containers, suggesting that evaporation in open containers contributes to the observed faster freezing of hot water. The conversation highlights a need for clarity regarding the mechanisms behind this phenomenon, with references to a mathematical explanation that attempts to elucidate the underlying physics. The vague nature of the proposed explanations raises questions about their applicability in controlled environments, prompting further inquiry into the conditions that influence freezing rates.
Einstein Mcfly
Messages
161
Reaction score
3
http://www.iflscience.com/chemistry/hot-water-freezes-faster-cold-and-now-we-know-why

I thought that this had never been shown to happen with closed containers. I always thought that this was an issue of open containers allowing for evaporation and hence a smaller amount of frozen water, and that if lids were put on then the cold froze faster.

Does anyone have any thoughts on the vague explanation proposed in this link?
 
Last edited by a moderator:
Chemistry news on Phys.org
I want to test a humidity sensor with one or more saturated salt solutions. The table salt that I have on hand contains one of two anticaking agents, calcium silicate or sodium aluminosilicate. Will the presence of either of these additives (or iodine for that matter) significantly affect the equilibrium humidity? I searched and all the how-to-do-it guides did not address this question. One research paper I found reported that at 1.5% w/w calcium silicate increased the deliquescent point by...
I'm trying to find a cheap DIY method to etch holes of various shapes through 0.3mm Aluminium sheet using 5-10% Sodium Hydroxide. The idea is to apply a resist to the Aluminium then selectively ablate it off using a diode laser cutter and then dissolve away the Aluminium using Sodium Hydroxide. By cheap I mean resists costing say £20 in small quantities. The Internet has suggested various resists to try including... Enamel paint (only survived seconds in the NaOH!) Acrylic paint (only...
Back
Top