SCIENCE
CHEMISTRY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Absorbs some heat
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Releases some heat
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Neither absorbs nor releases
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Absorbs exactly 3.34 x 10^5 J/kg of heat
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Detailed explanation-1: -The correct answer is to release heat. When water at 0°C freezes to form ice at the same temperature of 0°C then it releases heat. At 0°C, water discharges some heat to decrease the speed of molecules. When the water is cool enough its molecules are fixed at one position and they begin to vibrate.
Detailed explanation-2: -As soon as ice gets to zero it begins to melt. But freezing is a bit different. In fact, pure water can easily be cooled quite a long way below zero Celsius and stay as liquid water. We call this supercooled water.
Detailed explanation-3: -When water becomes a solid, it releases heat, warming up its surroundings. This makes freezing an exothermic reaction.
Detailed explanation-4: -As the liquid cools down, the amount of potential energy is reduced and the molecules start to move slower. When the water temperature reaches around 0°C, the molecules stick together and form a solid – ice. Even in this solid stage, the molecules are still moving – we just can’t see it.