This phenomenon has been observed, but not in all circumstances. The "MPEMBA EFFECT" was originally published to consider possible causes. (see link}
What Actually Happens There are several things that can help the hot pail freeze faster than the cold pail. Here are what is thought to be the most significant factors: The hot water is more likely to be supercooled. This means that the hot water's temperature is more likely to cool to temperatures below zero degrees Celsius. In the cold non-supercooled water, ice crystals form and float to the top, forming a sheet of ice over the top of the water, creating an insulating layer between the cooler air and the water. This ice sheet also stops evaporation. In the hot water that has become supercooled (thus, no longer hot) the water, when it does freeze, freezes throughout, creating more or less of a slush before freezing solid. Why is hot water more likely to be supercooled? Because hot water is less likely to contain tiny gas bubbles. Gas bubbles form from dissolved gasses as the water cools. When the hot water was heated, these dissolved gasses may have been driven out. In cold water, ice crystals use the tiny bubbles as starting points for formation (in physics, we call them nucleation points). But in the hot water, there are no bubbles, so there aren't as many starting points for the ice crystals. Dissolved gasses also lower the freezing point. Since heated gas is less likely to contain dissolved gasses, it's more likely to freeze first. Water in the hot water pail evaporates at a much faster rate than the cold water. This does two things. First, the process of evaporation is endothermic, which means it takes energy for something to evaporate. As a molecule of water evaporates, it leaves the surface of the water and flies into the atmosphere. Thus, in simplified terms, the molecule converted heat energy into kinetic energy (energy of motion). Since the hot water evaporates quicker than the cold water, it loses heat energy quicker than the cold energy. Second, since some of the hot water evaporates away, there is less water left to have to freeze. The hot water pail will melt the surrounding snow. Later, as it begins to freeze, the snow around the pail will freeze back so that it more closely "touches" the pail. The cold water pail is then only sitting in fluffy airy snow, while the hot water pail is in a form fitting ice-crust. The ice-crust will obviously conduct the cold better that the airy snow. Other factors, such as convection currents (the movement made as hot water rises while cool water sinks) may or may not play a role in this odd phenomenon.
yes
One is the temperature of the water could be warmerSecondly when an ice cube is in water, conduction takes place. The kinetic energy of the water particles more time.moves to the ice causing it to melt. When in air radiation or convection must take place which will take
No, it wouldn't. a sugar cube would melt a lot faster in a cup of Hot water. the hot water helps it desolve more evenly than cold water.
sand heats faster because it absorbs heat faster than water!!!!!!
A cylinder shaped ice cube will melt faster because it has a greater surface area than the rectangle-shaped ice cube has. Cubes of ice with less surface area will melt slower. Ice that has very low surface area has more ice concealed inside than it does on the outside. Therefore, ice cubes that have more surface area will melt faster... I hope this will help you.. :) ..
of course they can be cut into a square. if you peel the skin of and cut it into pieces you can cut it into a square, rectangle, and many other shapes.
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yes salt water does boil faster
It does NOT boil faster than water. It has higher boiling point AND lower freezing point. - Antifreeze boils at about 197 c.
A small amount of water will reach it's boiling point sooner than a large amount of water. It will not boil faster.
yes
Yes
there are already bubbles in it
possibly...
In most cases an equal volume of juice will melt faster than an equal volume of ice
Yes; because the rushing water will use (erosion) to wear it away faster than the temperature surrounding the ice cube in the air will
yes
Yes salt water does boil faster than fresh water. To be honest, if you put any kind of seasoning in a warming pot, it sparks a reaction.