Properties of Water-Physical, Thermal and Biological Characteristics of Water

You know that the 71% of the surface of the earth is covered with water. Water is the most available liquid in the earth surface. In this article, I am going to give you a commentary about what are the properties of water(Physical, Thermal and Chemical)?

You know that the accumulation of water on earth surface is mainly due to runoff and precipitation. So one of the main factors which affect the properties of water is its sources.

What are the properties of Water?

The Properties of water can be divided into physical, thermal and biological or chemical.

Physical Properties of Water


The colour is one of the important physical properties of water. The colour of the water is due to organic matter, leaves, peat etc..

The measurement of the colour of water can be done with the burgess scale or cobalt scale using a tintometer. The colour intensity of water is measured in terms of cobalt scale.

The unit of colour is that produced by one milligram of platinum cobalt in one litre of distilled water. For public water supply, the number on cobalt scale should not exceed 20, and preferably should be less than 10.

2.Taste and Odour

Taste and odour are the second significant physical properties of water. These two are mainly very hard to measure accurately because taste and odour is something that you need to feel it.

The main caused of taste and odour in water due to the presence of mineral salts, domestic sewage, organic matter, industrial wastes etc..The odour can be measured in terms of threshold odour number.


The temperature is one of the significant properties of water. Because for any purpose, the assessment of temperature is mandatory.

You can measure the temperature of the water with the help of a thermometer. For the domestic purpose, the range of temperature is between 20 to 100-degree Celsius.

4.Turbidity of Water

Turbidity is imparted by the colloidal matter present in water. Turbidity is the measure of the resistance of water to the passage of light through it.

The Standard unit of turbidity is parts per million( ppm). One ppm is equivalent to 1mg per litre. The permissible turbidity of domestic water should be in a range of 5 to 10 ppm. The turbidity can be measured with the help of

  1. Turbidity rod
  2. Jacksons turbidimeter
  3. Baylis turbidimeter
  4. Nephelometers.

5.Specific Conductivity

Specific conductivity is one of the electrical properties of water. The specific conductivity indicates the total dissolved solids in water. The measurement of conductivity can be done by an electrical conductivity meter.

6.Surface Tension

You may ever have thought about how you can float a paper on the surface of the water? It is because of a property of water called as surface tension.

The water molecules at the top of the surface of water can form bonds with each other and form an invisible film.

The surface tension is an essential water property for seawater. Because surface tension carries a significant role in the formation of waves. If there is no wave in sea water, oxygen diffusion will not take place which would affect aquatic organisms.

Thermal properties of water

Thermal properties of water

The water can absorb or release a large number of heats than several other materials. This is why water is widely used for cooling and heating in thermal process machines.

1.Specific Heat

Specific heat is the amount of energy or heat needed for raising the temperature of a liquid to one degree. Water has a high specific heat.

I think you may have felt the temperature of sand in beaches are more than the temperature of seawater. This is because of specific heat. The specific heat of water is 5 times that of sand.

2.Heat of Vapourization

Water has a high heat of vaporization. Water absorbs heat as it changes from a liquid to a gas; the human body can dissipate excess heat by the evaporation of its sweat.

3.Density of water

You know that the density of water is 1gm/cc or 1 kg/cubic meter. The water shows a maximum density at 4-degree Celcius. That means if there is rise or fall from 4-degree Celsius, its density will decreases.

Chemical Properties of Water

Water quality in developed and developing countries continues to deteriorate due to increased movement of refugees in developing countries and natural disasters like flooding and droughts

So its very important to check the chemical properties of water before its use.

1.Ph of Water

Ph is the first chemical property of water that you need to check in your laboratory. Ph is the negative logarithm of hydrogen ionic concentration in water. The range of ph varies from 0 to 14.

  • If the value of ph is less than 7 then your water is acidic.
  • If the value of ph is equal to 7 then your water is neutral.
  • If the value of ph is more than 7 then your water is alkaline.

The measurement of ph can be easily done with ph meter. The principle behind the ph measurement is to determine the activity of hydrogen ions by means of a reference electrode and standard hydrogen electrode.

The normal range of ph in surface water ranges from 6 to 8.5

2.Acidity of water

The acidity of water is another important chemical properties of water. The acidity of a water is its capability to react with a strong base.

Read More: How to measure the acidity of water?

3.Alkalinity of water

The alkalinity of water is the capability of water to neutralize a strong acid. The salts and weak acids are the main reason for the alkalinity of water.

Read More: How to determine the alkalinity of water?

4.Hardness of water

While you traveling to a new city, you may have noticed some changes in there water. That water may be very difficult to form lather with soap. This is because of the presence of hardness of water.

The hardness of water is due to the presence of dissolved calcium and magnesium ions. Read more about the determination of hardness here.

5.Chlorides in water.

Chloride in water is a chemical property, but you can felt it taste physical. Chlorides are used widely for the purification of water.

The water treatment with chlorides results in a salty taste to the water. The maximum range or level of chlorides for drinking water is 250mg/litre of 250 ppm.

Read More: How to determine the chloride content in water?

Hope you can understand what are the physical, thermal and chemical properties of water. If you have any doubt, please comment below.

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