Question

What happens to the properties of water, in particular, density, at sea level when ice melts and the temperature increases to 4 degrees celsius? Give an example of this in practical terms. No practical answer can be repeated, you must use an original example. Do not use ice as the example.

Answer 1

We know that, from our common observations in everyday life, that when a substance (or matter) is heated,it expands i.e. its volume becomes larger as the temperature is increased and as

the density falls. But our observations greatly flaws in case of properties of water at .What actually the case is that the piece of ice at is less dense than water at and when we start heating the ice, it melts and the density of water gradually increases up to and the volume decreases accordingly. Then after things turn back to normalcy again and the volume increases as temperature is increased after i.e at ,the water has Maximum Density and Minimum Volume. This anomalous behavior of water from to is known as the Anomalous expansion of water.

Things are clarified from the below plots-

A practical example of this can be seen in the case of soft drinks bottle stored in the refrigerator. When the temperature of the refrigerator drops below ,from the above graph you can see that the volume increases and the empty space that is kept above then come into use otherwise the bottle would have been busted.

In cold countries, where in winter the lake and ponds all freeze, but still the marine animals face no threat for their survival as below the ice sheet, there is still water and the ice being at is less dense than water, comes on to the surface and float and due to its bad conductivity properties, it doesn't allow the cold to get inside the water of the pond and the water below is still above .