Rain is the chief source of water.
The other sources of water are lakes, rivers, oceans, seas and streams.
Therefore, water is one of the gifts of Nature to Man. Water is the basic
necessity of all living things as it sustains life on Earth. Water is required
for agricultural, environmental, household, industrial and recreational
activities.
Rain is the chief source of water.
The other sources of water are lakes, rivers, oceans, seas and streams.
Therefore, water is one of the gifts of Nature to Man. Water is the basic
necessity of all living things as it sustains life on Earth. Water is required
for agricultural, environmental, household, industrial and recreational
activities.
Water plays three different roles on the
earth. It is ice at the poles, water in rivers and lakes, snow in the glaciers
and vapour in the atmosphere. Most of the water is in the oceans and seas. Water is always on the move. The Sun’s energy causes
water to evaporate from oceans and lakes into the atmosphere. Plants and
animals also release water vapour into the atmosphere as they breathe. When the
atmosphere cools, water vapour condenses; making clouds that might produce rain
or snow. Thus, the movement of water on, in, and
above the Earth is known as Water Cycle or Hydrologic Cycle. Thus, earth’s
water is always in movement and is always changing states, from liquid to vapour
to ice and back again.
Water exists in all the three states of
matter on the earth. It takes different forms.
They are: Clouds in the sky. Sea water in oceans and seas. Ice bergs in polar regions. glacier in
mountains. Fresh water in lakes, rivers, ponds and streams. Aquifers in ground
water.
How is water molecule
formed?
Water is formed when
hydrogen gas and oxygen gas chemically combine. Water is formed when oxygen and
hydrogen atoms share electrons as electrons are responsible for chemical
reaction.
Hydrogen atom has only one
electron in the outermost orbit. Oxygen atom has six electrons in the outermost
orbit and two electrons in the first orbit, contributing to a total of 8
electrons totally. Off the 6 electrons in the outermost orbit, four electrons are
non-bonding pairs or paired electrons. They do not take part in the bond
formation. But the remaining two electrons are unpaired or lone electrons. They
bond or pair with one electron of hydrogen atoms forming octet. Hence water is
formed.
In a water molecule, oxygen
atom remains at the centre, Hydrogen
atoms to the sides. A water molecule looks like a tetrahedron. H-O-H angle between
paired electron pair is 109.5 degrees. H-O-H angle between unpaired electrons
is 104.5 degrees, resulting in a distorted tetrahedron arrangement. This is
because, the two non-bonding, paired electron pairs of oxygen atom
remain closer to the oxygen atom; exert a stronger repulsion against the two
unpaired, covalent bonding pairs, effectively pushing the two hydrogen atoms closer
together. Therefore water is a covalent
compound as the electron pair are shared during the formation of water.
Water is a chemical compound. A molecule
of water contains two hydrogen atoms and one oxygen atom. In other words the ratio of
hydrogen to oxygen is 2:1, the ratio of hydrogen to water is 1:1, and the ratio
of oxygen to water is 1:2.
2H2 + O2 = 2H2O
Two atoms of Hydrogen combine with one
atom of oxygen to form two molecules of water. This reaction is also known as
combustion reaction as hydrogen is combining with oxygen. This reaction is an
exothermic reaction as tremendous energy is released after the formation of
water. Hence,
2H2 + O2 = 2H2O + ENERGY (57J)
If we analyse the above
reaction, water, a liquid, is formed when two gases are chemically combined. If
we try to understand the physical properties of hydrogen and oxygen gases,
hydrogen is a combustible gas and oxygen is a supporter of combustion. That
means hydrogen gas can work as fuel. The question now is whether we can we reverse
the reaction. Yes. It can be reversed. This reaction requires energy to be
supplied. Therefore the reaction is an endothermic reaction. By the method of
electrolysis of water we can get decompose water into hydrogen gas and oxygen
gas. Hydrogen gas can be used as can be used as a fuel.
2H2O + ENERGY = 2H2 + O2.
This reaction makes certain facts very clear.
The end product, hydrogen gas is a fuel. But the starting product is water.
Hence acidified water is also a fuel. The amount of acid added is negligible.
Therefore Water is a fuel and is a form of energy.
Too much energy is required in this process. According to Science Daily, (https://www.sciencedaily.com/releases/2016/03/160310080822.htm) researchers have now doubled the efficiency of the reaction. Researchers have
boosted the efficiency of water electrolysis by applying a layer of copper
atoms in a conventional platinum electrode. Thus, reaction intermediates could disappear
a bit more easily from the catalyst surface. The modified system generated
twice the amount of hydrogen than a platinum electrode without a copper layer. The
research team published these results in the journal Nature Communications.
Hence we should safeguard
and protect water sources. It is a lifeline of all activities. Demand for water has exceeded the supply of water as rains
are becoming scarce. Human population is increasing; demand for water is
growing day by day. Major aquifers are depleting throughout the world and as a
result the ground water supply is drying up. Climate has a significant impact
on world water resources and water cycle. Many pollutants and sewage water is
discharged into natural and fresh water by developing nations. This threatens
the shrinkage of total water supply on the earth.
There is a need to keep the water pollution free in rivers
and lakes. There is a need to purify the sewage water before discharging into
the rivers. Purification of water should start from home. Purifiers should be
installed compulsorily in all households in all places to preserve the 100%
purity of water. Therefore water is a renewable source of energy.
" Save Water to Survive"
"Save Water to Save Earth"
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