Heat

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The heat energy absorbed at constant temperature during transformation of solid into liquid phase. It is the energy needed to weaken bonds between atoms/molecules in the solid without changing tempera…

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The temperature remains constant at 0°C (melting point) even though heat is being supplied. All the heat energy is used to break the bonds between ice molecules to convert ice into water, not to incre…

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The amount of heat energy absorbed at constant temperature by unit mass of a liquid to convert into gaseous phase. For water, it is 2256 kJ/kg or 540 cal/g. This energy breaks bonds between liquid mol…

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Regelation is the phenomenon where ice converts to liquid due to applied pressure and re-converts to ice when pressure is removed. Example: When a wire with weights passes through an ice block, it mel…

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The melting point of ice decreases below 0°C when pressure is applied. At 0°C, pressurized ice converts to water. When pressure is removed, the melting point returns to 0°C and water converts back to …

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Water shows unusual behavior between 0°C to 4°C - it contracts when heated instead of expanding. At 4°C, water has minimum volume and maximum density. Above 4°C, it behaves normally and expands when h…

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Water has maximum density at 4°C. At this temperature, its volume is minimum. This is why water at 4°C sinks to the bottom in lakes and rivers, helping aquatic life survive in cold regions.

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In Hope's apparatus, when ice-salt mixture cools water from the middle, water at 4°C (higher density) moves down. When temperature goes below 4°C, density decreases and this water moves up. This shows…