Is it true that hot water freezes quicker than cold water and why is this?
It depends on your terminology – “quicker” is not an exact term. Side-by-side, with the exact same amounts of water in similar containers, hot water will decrease in temperature at a faster rate, but the cold water will turn into ice first. However, these experiments are sometimes affected by two conditions – when near-boiling water is used, it affects the amount of water used (some of it evaporates during boiling) and also boiled water has fewer impurities, so in some cases it can be seen to freeze first. The amount of water used has to be measured AFTER the heating, not before. Think of it this way – if you have the same amounts of water, side-by-side, hot and cold – the cold water starts out closer to the freezing point. Even if the hot water reduces in temperature more rapidly, at some point, in order to reach freezing first, it would need to “catch up” with the cold water. At this point, you would have 2 containers identical in temperature and volume, and essentially identical – s
