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प्रश्न
Give reasons: Lakes freeze from top towards bottom.
उत्तर
During winter, the temperature of lake water keeps on decreasing. Since cold water is heavier, it moves towards the bottom.
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संबंधित प्रश्न
Why is it said that-
Water is a universal solvent.
Why should a glass bottle completely filled with water never be kept in a freezer?
Define the following.
Boiling point
If same mass of liquid water and a piece of ice is taken, then why is the density of ice less than that of liquid water?
Melting point, enthalpy of vapourisation and viscosity data of \[\ce{H2O}\] and \[\ce{D2O}\] is given below :
| \[\ce{H, O}\] | \[\ce{D2O}\] | |
| Melting point / K | 373.0 | 374.4 |
| Enthalpy of vapourisation at (373 K)/kJ mol–1 | 40.66 | 41.61 |
| Viscosity/centipoise | 0.8903 | 1.107 |
On the basis of this data explain in which of these liquids intermolecular forces are stronger?
Write two reactions to explain amphoteric nature of water.
The freezing point of water ______ with an increase in pressure.
What are the physical properties of pure water?
Which of the following ion is responsible for the temporary hardness of water?
The density of gold is 19 g/cm3. If 1.9 × 10−4 g of gold is dispersed in one litre of water to give a sol having spherical gold particles of radius 10 nm, the number of gold particles per mm3 of the sol will be ______ × 106.
