Imagine the Earth where there would be no water! Rivers dried up, no blue oceans across the globe, no rainfall and no fresh water, no presence of water anywhere. This thought itself sends chills down the spine!
Water is one of the most important needs for survival. It is the source of livelihood. Water has end number of uses in our day to day life. Be it cooking, bathing, washing, gardening or any other domestic purposes, water is needed for everything. The whole world requires water not only for domestic but also for commercial and industrial purposes.
Fire and water are considered as enemies. One important use of water is putting off the fire. Water is indeed the best way to put off any fire. If we put anything on fire, it burns but why is water the only thing used to stop anything from burning. Why is the compound water which is made of flammable hydrogen and oxygen atom puts off fire but doesn’t get burned?
The answer to this question is quite simple. We cannot burn anything which is already burnt. The same applies to water. Water is already burnt and so fire cannot burn the water again. This is quite shocking a burnt thing is being used to put off anything which is burning. But there is a very basic science that is responsible for this process.
As we all know that water is made up of hydrogen and oxygen. Hydrogen is flammable and oxygen is a supporter of combustion. Anything which reacts with hydrogen in presence of oxygen is referred to as burning. When combustion of hydrogen happens in presence of sufficient oxygen atoms, it leads to the formation of water. The two atoms of hydrogen form covalent bond with one oxygen atom. The oxygen atom shares the valence electrons with hydrogen atoms and releases energy.
The combining process of hydrogen and oxygen molecules involves the release of a large amount of energy and a violent reaction. This is how they combine. H-O-H bonds are very strong and cannot be broken easily. It requires a lot of external energy to break.
Since the oxygen atom cannot be released from water molecules easily, the compound water is not able to react with the oxygen present in the atmosphere. This, in turn, would not let combustion to happen and the water would not act as a flammable substance.
The hydrogen bonding is very strong as attractive forces are acting between the molecules. This is the reason why water molecules do not break. Even when we heat the water and try to burn it, it does not convert into oxygen and hydrogen, but it changes its state from liquid to gases and evaporates in the form of water vapour; the molecules of water still being the same.
It is only because water is a compound formed due to burning of hydrogen that it cannot burn again. The unique liquid water is thus used as the best thing to put off fire as it will never burn!