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प्रश्न
Describe an experiment to demonstrate that water absorbs heat during boiling at a constant temperature.
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उत्तर
BOILING POINT OF WATER AT CONSTANT TEMPERATURE:
Take some water in a beaker. Suspend and clamp a thermometer in a beaker in water so that the bulb of thermometer remains in water without touching bottom and sides of the beaker. Supply heat by the burner and note the temperature at room temperature (20°C nearly)
Record the temperature after every minute. The temperature rises and as it reaches 100°C water starts boiling. Though heat is being supplied temperature does not rise i.e. it remains constant at 100°C and bubbles formed are seen. Thus, the boiling point of water is 100°C and at boiling point heat supplied is absorbed by water at a constant temperature. Because this heat is being used to change every molecule of water into vapours.
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संबंधित प्रश्न
A liquid can change into vapour state at a fixed temperature.
Water into steam on heating is called freezing.
Choose the correct statement of the following
A sample of water under study was found to boil at 102°C at normal temperature and pressure. Is the water pure? Will this water freeze at 0°C? Comment.
Evaporation of a liquid at room temperature leads to a ____________ effect.
____________ is the change of solid state directly to vapour state without going through the ____________ state.
The phenomenon of change of a liquid into the gaseous state at any temperature below its boiling point is called ____________.
Why does the temperature of a substance remain constant during its melting point or boiling point?
We would have observed that the plate that covers the cooked food items has water droplets inside. Why? Explain.
Explain the terms boiling.
