Does less water freeze faster than more water?

Answer 1

No. The important factor is the surface area of the water that is exposed to cold conditions. A large, thin pan of water will freeze just as quickly as a smaller, thin pan of water if the ratio of surface area to volume is the same. The reason a large bottle of water freezes more slowly than a smaller one is that less of the water is exposed to the outside of the container, where its heat is lost. And, as the ice forms inside the container, it further reduces the rapidity of heat loss to the air around the container.

Answer 2

No. There is a myth that hot water freezes faster than cold water because in cold climates where household pipes will sometimes freeze in the winter, the hot water pipes invariably freeze before the cold water pipes do. But this happens because the water that is in the hot water pipes was once heated in the hot water heater, and heating water drives out dissolved gases. By the time this water ends up sitting in a pipe waiting to freeze, it has already cooled off. So what you really have are two pipes, side-by-side -- one of them had previously been heated (degassed), then was allowed to cool, and the other pipe's water had never been heated. The dissolved gases that are still present in the cold water pipe cause it to freeze at a lower temperature, which we see as "freezing slower." (Dissolving anything in water will lower its freezing point and raise its boiling point -- this is why your car's engine coolant and anti-freeze are the same thing. Google "colligative properties" for more details.) If you put a glass of hot water and a glass of cold water in the freezer, the cold water will freeze first. But if you heat a glass of hot water, then allow it to cool to room temperature, and then put it in a freezer along with a glass of room temperature water that was never heated, the previously heated water will freeze faster than the never-heated water.