Water-Need For Living Beings


The term Water is denoted by ‘the chemical elements consisting of (hydrogen-H2) and (oxygen-O3) and exist in gaseous, liquid, and solid states. It is the most abundant and necessary of the compounds. Tasteless and odorless liquid at room temperature, it has the important ability to dissolve many other substances.

Properties Of Water:-

– Water is the major abundant molecule over the earth’s surface.

– Occupied Almost 70% Planet’s Surface.

– Water is the only common object found in nature, all states of matter, chemical properties.

Form Of Water

Solid water – The Ice is frozen water, When the molecules water freezes, its molecules separate from each other and the ice becomes less dense than water. This means that the ice floats on the water because it is lighter than the same amount of water. Water accumulates at 0 ° C or 32 ° F.

Liquid water- It’s wet and fluid. Which is the form of water molecules, Liquid water is used in a variety of ways, including washing and drinking, that is called Liquid water molecules.

Water-gas – The concentration of Steam is always present in the air around us. You can’t see it When water is boiled, it changes from a liquid to a gas or water vapor. When some water vapor cools, it looks like a small cloud known as steam. This vapor cloud is a smaller version of the clouds that we see in the sky. At the sea surface, steam is produced at 100 ° C and 212 ° F.

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Fig. 1: Form of Water.

Properties Of Water

1. Water’s High Heat Capacity & Water’s Heat of Vaporization:

There is the ability of a molecule to absorb heat energy is called heat capacity, the high heat capacity of water is due to the bonding of hydrogen between water molecules. When heat is absorbed, hydrogen bonds break and water molecules can move freely. When the water temperature drops, hydrogen bonds are formed and release a significant amount of energy. Any liquid in water has a specific heat capacity. Specific heat is defined as the amount at which one gram of substance must be absorbed or one gram of temperature to be changed to one degree Celsius. For water, this amount is one calorie or 4.184 joules. Water in liquid form has an unusually high boiling temperature, close to 100. C. As a result of the network of hydrogen bonds between water molecules, more energy is needed to convert one gram of liquid water into vapor, which requires energy called evaporative heat. The evaporation value of water is 40.65 kJ / mol.


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Fig. 2: Water’s High Heat Capacity.

2. Density of Water and Ice:

There is a density of water molecules dependent on its heat temperature. When room temperature has cooled, the result of liquid water becomes extends with density. But there are reached on approx 4 deg Celcius, H2O reaches its maximum density. Then according to the situation, it’s cooled, yet it is found less dense. Whereas the solid form of water is found most denser compared to the liquid form of the water body. That’s why the solid substances will cavity in the liquid. The melting point of ice is 0 deg Celcius at pressure.

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Fig. 3: Density of Water and Ice.

3. Miscibility and Condensation of Water:

Water is not mixed with many liquids, including ethanol in all proportions. Water and most oils disappear according to the increasing concentration from the top usually forming layers. This can be predicted by comparing the poles. Relatively polar composite water can be mistaken for high polar liquids such as ethanol and acetone, while low polarization mixtures can be as invisible and weakly soluble as hydrocarbons. As a gas, water vapor is entirely forgotten by the air. On the other hand, the maximum pressure of water vapor, which is thermally stable with a liquid (or solid) at a given temperature, is equal to the total atmosphere. The pressure is relatively low. It cools, starts at about 22 degrees centigrade, the water begins to condense, defines a dew point, and forms a mist or dew. The reverse process prevents the fog from burning in the morning. If the humidity rises to room temperature, for example, through a hot shower or bath, and the temperature remains the same, the steam quickly reaches the pressure to change phase and then condenses as a drop of water in a few minutes. when the vapor pressure of water in the air is in equilibrium with the vapor pressure due to water (liquids); water (or ice, if cold enough) will not lose mass by evaporation when exposed to saturated air. Because the amount of water vapor in the air is small, the relative humidity, the ratio between the partial pressure due to water vapor and the partial saturated vapor pressure is much more useful. Vapor pressure above 100% relative humidity is called super-saturated and can occur if the air is cooled rapidly, for example, suddenly rising in a current.

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Fig. 4: Miscibility and Condensation of Water.

4. Compressibility of Water:

The term water compressibility is a function of temperature and pressure. As we know that pressure, at the 0 deg Celcius in the bounded of zero pressure the compressibility is about 5.1*10^10 Pa-^1. There is a zero-pressure limit define as compressibility archives mini value is 4.4*10^10 Pa-^1, which about 45 deg Celcius before increasing again with temperature. When we found low compressibility of the water that can be called very deep water about 4 km, there is an estimated pressure of about 40 Mpa.

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Fig. 5: Compressibility of Water.

5. Triple Point Of Water:

In the triple point of water, there are temperature and pressure at which solid, gaseous, and liquid water coexist in equilibrium is known as the triple point of water.

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Fig. 6: Triple Point Of Water.

6. Electrical Conductivity Of Water Molecules:

An electrical conductivity observable in water molecules is the result of ions of mineral salts and CO2 dissolved in it. The Co2 forms carbonate ions in water. In pure water, sensitive equipment can detect a very slight electrical conductivity of 0.055µS/cm at 25 deg Celcius. As well know that that water can also be electrolyzed into oxygen and H2 gaseous but there are found an absence of dissolved ions this is the very low process, like the very little current is conduct pass.

7. Dipolar Properties:

there are the most essential characteristics of water, especially in polar nature. The water molecules from an angle, with H2 atoms at the tips and O3 at the vertex. As well known to say, its O3 has more electronegativity than hydrogen with the O3 has a partial negative charge. This is found to change variations called a dipolar effect.

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Fig. 7: Dipolar Properties of water.

8. Capillary Action Of Water:

The water flows as the tube until there is enough water such that gravity balances the adhesive force. Its rule is most essential in biology.

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Fig. 8: Capillary Action Of Water.

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