Specific heat of water

Water is such a habitual attribute of our everyday life that it is probably difficult to find a person who, without any professional reason, thought about its physical and chemical properties. But, if you have to start talking about it in this context, you often hear the thesis that this problem is of little interest because of the fact that the water has long been known and explained to the level of axioms. However, this is not at all the case. The nature of the chemical compound known to us under the name of water has not been sufficiently investigated so that it can be asserted that we know everything about it.

Indeed, the water is everywhere around us, but from the point of view of its physico-chemical nature, it is very interesting that it is a virtually universal solvent. This quality, in turn, is determined by a whole list of water properties, which make the dissolution potential of the connection universal.

For example, everyone knows from school that when the temperature increases from 0 C to +4 C, an increase in the density of matter occurs, after which this index itself begins to gradually decrease. This peculiar change in the density parameters is explained by the peculiarities of the structure of water molecules and the nature of the interactions between them. It is also interesting to see such a process, during which the values of such parameters as the specific heat of water, density and thermal conductivity change in the same abrupt manner. As an example, we can cite this dependence. It is established that the specific heat of water is almost twice as high as the same index for ice.

To explain this phenomenon, it should be recalled that, in fact, is a heat capacity. To better understand the subject of the definition, the term specific heat should be chosen. This is the quantity denoted in physical formulas as "c", which shows how much heat energy should be spent to ensure an increase in temperature of 1 kg of the substance (in this case water) per degree.

So, near water, the heat capacity is anomalous not only on the basis of its significance. It is proved experimentally that the specific heat of water has completely different values at different temperatures, and the character of this dynamics is an unusual dependence. The heat capacity of water falls in its value only in the temperature range from 0 to 37 C. If, then, the temperature is increased, the heat capacity will also increase.

During numerous experiments it was established that the lowest value of the specific heat of water is fixed at a temperature value of 36.8 C. Reading these lines, does this number not cause any associations? Of course! This is an indicator of the body's normal temperature not only of man, but also of the overwhelming number of all warm-blooded. In this indicator, there is another interesting detail. The fact is that the dynamics of the passage of specific heat parameters is characterized by a kind of symmetry. It consists in the fact that at temperatures below zero there is also a minimum heat capacity value. It is in the value of -20 C. It is this that characterizes such a parameter as the specific heat of water, a table that is used to quickly determine the values of thermal conductivity.

The reason for this phenomenon should be explained on the basis of an analysis of the physical properties of water. Water is a chemical compound with a very high heat capacity. This means that, being able to absorb a significant amount of heat, the water itself, at the same time, heats up insignificantly. Comparing with other substances, we see that the specific heat of water in whole 5 times exceeds the same parameter for sand and 10 times for iron.

It is this ability of water to accumulate huge reserves of heat energy that ensures the stability of the temperature regime on the planet, allows to mitigate the negative consequences of temperature jumps in connection with the change of the seasons, hours of the day. Water, due to its peculiarities in the heat capacity, acts as the main thermoregulator of the Earth.