We start our day with a little (big) bit of chemistry everyday. There is a very active Chemistry lab in every home which plays an important role in feeding the members. Yes, you guessed it right, I’m talking about the Kitchen where the different ‘masalas’, vegetables, some acids, bases and salts along with many other compounds including the commonly used alkaloids (of tea, coffee) too react to make our daily living too enjoyable with the tasty food and beverages.
“Chemistry“, though not in its present form, had a great (good) beginning with the discovery of fire; when man realized that cooked food is better than raw. This gave him the idea to test anything with fire.
In ancient times, when the population was less, we had enough resources to feed all. But now, the population is increasing in geometric progression; in an explosive manner. In the good old times, men used to increase the area of cultivation to meet the increasing needs. But now, we’ve reached the limit and no more expansion of agriculture land is possible. We are heading towards a world of adversities. Estimates say that the world population will reach 8 billion by 2025. Further, we have used up the available land to provide shelter to the ever increasing population and for industrialization. Many have even converted farms to plots and constructed mansions over there.
AN URGENT NEED! INCREASE PRODUCTION WITH AVAILABLE LAND RESOURCES
We must increase production by at least 50% to feed the population.
Now to feed the population, the only way out is to produce more food from the available land.
Here comes the role of Chemistry! The aforesaid task is possible only with proper use of Chemistry along with Biology and Biotechnology and other emerging scientific technologies to the fullest.
In feeding the nation, one of the most important constraints is the limited space available for cultivation. It’s my humble suggestion that every house should have a kitchen garden to produce at least some vegetables and fruits. This will enable us to cultivate the vegetables and fruits we like and be sure that we are using uncontaminated food.
ROLE OF CHEMISTRY IN BETTER AGRICULTURE
The yield decreases year after year because of the reduced fertility of soil caused by repeated cultivation of same crops. So, the supply of the lost nutrients through manures and fertilizers will ensure better yield. But, there is one thing to keep in mind; the fertilizers we use must not have counter effects. These are to be tested and different situation. Proper use of chemistry can result in bettering the yield per area. Some entrepreneurs have already proved that the scientific farming can produce excellent results. Terrace farming and similar projects have found astonishing results. Here also the main facilitator is Chemistry.
UNDERSTANDING THE NATURE OF SOIL
The nature of soil differs from place to place. So, to have a detailed analysis of the nature of soil we choose for cultivation is very much essential. Chemistry will help here in determining the nature of soil and suggest the right type and amount of chemicals and fertilizers required to make it the most productive. Soil study should not be limited to typical places and the results should not be generalized. In cultivation, “One fits all” type of policy will not work. Before starting cultivation a soil study can be conducted and proper treatment of soil will help producing better yield.
WATER PROBLEM AND CHEMISTRY: “MORE CROP PER DROP”
The scarcity of water for irrigation is a problem commonly felt by farmers, especially in hot regions. As we have learnt, about 70% of earth’s surface is covered by water. But, the sad fact is that only 2.5% out of this only is fresh water. And most of these are trapped in inaccessible areas like the Antarctic caps, Greenland, soil moisture etc. Only 1% of the total water on earth is available for ready use.
Chemistry will come in here for a good help. With the proper use of chemical reactions the waste water used for various purposes such as bathing, washing etc can be converted to water suitable for irrigation.
Chemistry along with other technologies can help in cost effective and energy efficient desalination of water and convert it into usable water.
Drip irrigation with facility to add nutrients in the right proportion can save water as well as provide nutrient effectively and efficiently. There is a commonly used slogan “More crop per drop”. This must be our aim too. Everything we do must be to increase the yield with reduced water wastage.
Providing safe drinking water has also been taken up as a responsibility of chemistry. After purification of water, it loses many useful minerals also. In purification as well as in adding the right minerals in the right proportion, chemistry comes to help.
CHEMISTRY IN REDUCING WASTAGE OF FOOD
Human being has undergone the transformation from hunter gatherer to agricultural to industrial to provider of goods and services. It’s a common observation that most of the middle class and above families depend upon ready made food as well as ready to cook food. In the consumerist society, the role of preserved food is very important.
Chemistry helps us to eliminate wastage of food. At one part there is problem of plenty and in other part people are starving. The population in cities is too much dependant on processed / preserved food. Chemistry plays a very important role in preserving food. Ensuring the appropriate use of preservatives will ensure a healthy nation dependant on processed food. While using the chemicals, poisonous and those having after effects should be avoided
Non reacting gases are filled in packed food like chips and snacks to prevent damage. This can be tried in various other items too.
Chemical Sensors are now developed for easy monitoring of ripening of food. This will ensure timely transportation of fruits before they are over ripened and wasted before they reach the market for consumption.
INCREASING YIELD WITH CHEMISTRY
The role of Chemistry is not just limited to the development of fertilizers and water treatment and purification. It can be involved in a more constructive and scientific way. By proper use of chemicals which ‘catalyses’ the growth of plants and effectors for sudden growth, flowering and ripening, the yield can be increased and that too in less time.
INCREASING TOLERANCE WITH CHEMISTRY
Chemistry helps to increase the tolerance level of crops. Tolerance means the ability of a plant to resist lack of proper conditions like water, nutrients, temperature etc for their growth and sustenance. Some Chemicals can improve tolerance drought conditions where the seeds and plants can withstand lack of proper water supply and can resist extinction. Proper use of chemicals can develop immunity to deceases.
CHEMISTRY TO EMPOWER BIOTECHNOLOGY TO FFED THE WORLD
Genetic crop improvement is another possibility where also chemistry has its own role to play in identifying the high yield varieties and effecting the genetic researches.
One of the essential nutrients is phosphate. Phosphates required for plant growth are close to exhaustion. Proper planning is to be planned and executed. The ban on usage of bone powder in some regions also decreases the source of phosphates available for cultivation.
Nitrogen is a part of all living cells and is a necessary part of all proteins, enzymes and metabolic processes involved in the synthesis and transfer of energy. Nitrogen is a part of chlorophyll, the green pigment of the plant that is responsible for photosynthesis. Helps plants with rapid growth, increasing seed and fruit production and improving the quality of leaf and forage crops.
Nitrogen often comes from fertilizer application and from the air. Repeated cultivation decreases the nitrogen in soil. Chemicals can inhibit denitrification as well as provide soil nitrogen by application of nitrogen rich fertilizers.
Chemicals like Thiamethoxam activate proteins and help the plants grow fast. More research can be initiated to find such chemicals so that the yield can be multiplied. If chemicals which enhance the absorption of nutrients are formulated, it will increase the crops and vegetables with less investment. More areas were Chemistry can help in bettering the food production can be explored, engineered and actualized with a purpose to feed the growing world population.
NANOTECHNOLOGY TO HELP CHEMISTRY IN INCREASING AGRICULTURAL YIELD
Nanotechnology comes to help in chemical methods of increasing yields in many ways. It helps in ion concentration, low energy desalination and enables better absorption of nutrients and other chemicals. Low energy desalination using nanotechnology improves energy efficiency.
FOOD WASTAGE AND CHEMISTRY
Chemistry can eliminate wastage of food. The food packets are marked with “best before dates” which are often overlooked or unlooked by many. Proper ways of preservation without affecting the health of individual can be invented and put into practice.
NEED OF EXTENSIVE RESEARCH
Much extensive research has to be sanctioned and started urgently to evolve better methods of cultivation, seed treatment, preservation, distribution etc. We have only a limited time to act. We have all the technologies to delay or outcast the imminent atrocities, but they are still waiting in the shelves.
The studies conducted at one place of the country and the measures suggested cannot be applied as such for other parts of the country. “You have to be well fed to be a conservationist”; it’s a saying which suggests that the policies and programs are made by well fed people with no practical experience in cultivation. To remove this disparity, experienced farmers and agriculturists from different parts of the country must be included in while taking policy decisions.
The social hurdles and political interference delay the decisions. But, it’s high time that a social awareness and consensus be developed and the best suited plans and methods are implemented so that the yield is raised to the required level.
Chemistry has been helping us from time immemorial for feeding the world and has a more important role in the tough times ahead when the population is increasing and we fail to control well the exploding population. Proper advancement in technology aided with Chemistry can help feed the growing world population. Let’s hope for a better tomorrow, a healthy world with sufficient resources and food actualized by proper use of the wonders of Chemistry.
- An element ‘A’ exists as a yellow solid in standard state. It forms a volatile hydride ‘B’ which is a foul smelling gas
and is extensively used in qualitative analysis of salts. When treated with oxygen, ‘B’ forms an oxide ‘C’ which is
a colourless, pungent smelling gas. This gas when passed through acidified KMnO4 solution, decolourises it. ‘C’
gets oxidized to another oxide ‘D’ in the presence of a heterogeneous catalyst. Identify A,B,C,D, and also give the
chemical equation of reaction of ‘C’ with acidified KMnO4 solution and for conversion of ‘C’ to ‘D’.
- (a) An organic compound ‘A’ with molecular formula C5H8O2 is reduced to n-pentane on treatment with Zn-Hg/
HCI. ‘A’ forms a dioxime with hydroxylamine and gives a positive lodoform test and Tollen’s test. Identify the
compound A and deduce its structure.
(b) Write the chemical equations for the following conversions:
(not more than 2 steps)
(i) Ethyl benzene to benzene
(ii) Acetaldehyde to butane – 1, 3 – diol
(iii) Acetone to propene 5
- Give reasons for the following:
(a) Transition metals have high enthalpies of atomization.
(b) Among the lanthanoids, Ce(III) is easily oxidised to Ce(IV).
(c) redox couple has less positive electrode potential than couple.
(d) Copper (I) has d10 configuration,while copper (II) has d9 configuration, still copper (II) is more stable in
aqueous solution than copper (I).
(e) The second and third transition series elements have almost similar atomic radii.
- (a) A blackish brown coloured solid ‘A’ when fused with alkali metal hydroxides in presence of air, produces a
dark green coloured compound ‘B’, which on electrolytic oxidation in alkaline medium gives a dark purple coloured
compound C. Identify A, B and C and write the reactions involved.
(b) What happens when an acidic solution of the green compound (B) is allowed to stand for some time? Give the
equation involved. What is this type of reaction called?
- (a) Calculate the standard free energy change for the following reaction at 250C
Predict whether the reaction will be spontaneous or not at 250C. Which of the above two half cells will act as an
oxidizing agent and which one will be a reducing agent?
(b) The conductivity of 0.001M acetic acid is 4 x 10-5S / cm. Calculate the dissociation constant of acetic acid, if
for acetic acid is 390. 5S cm2/mol.
Categories: plustwo chemistry Tags:
Categories: plustwo chemistry Tags:
1. Some basic concepts in Chemistry
Importance of Chemistry, physical quantities and their measurement in Chemistry, SI Units, uncertainty in measurements and use of significant figures, Unit and dimensional analysis, Matter and its nature, laws of chemical combinations, atomic, and molecular, masses mole concept, molar masses, percentage composition and molecular formula, chemical stoichiometry.
2. States of matter
Three states of matter, gaseous state, gas laws (Boyle’s Law and Charles Law), Avogadro’s Law, Grahams’Law of diffusion, Dalton’s law of partial pressure, ideal gas equation, Kinetic theory of gases, real gases and deviation from ideal behaviour, van der Waals’ equation, liquefaction of gases and critical points, Intermolecular forces; liquids and solids.
3. Atomic structure
Earlier atomic models (Thomson’s and Rutherford) , emission spectrum of hydrogen atom, Bohr’s model, of hydrogen atom, Limitations of Bohr’s model, dual nature of matter and radiation, Heisenberg uncertainty principle, quantum mechanical model of atom (quantum designation of atomic orbitals and electron energy in terms of principal, angular momentum and magnetic quantum numbers), electronic spin and spin quantum numbers, Pauli’s exclusion principle, general idea of screening (constants) of outer electrons by inner electrons in an atom, Aufbau principle, Hund’s rule, atomic orbitals and their pictorial representation, electronic configurations of elements. Read more…