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Extraction of Essential Oil by Steam Distillation of Tulsi (Ocimum Basillicum)

Extraction of Essential Oil by Steam Distillation of Tulsi (Ocimum Basillicum)

Essential oils are insoluble in water and evaporate easily. We can obtain essential oil from plant tissues by distillation or extraction processes. Generally essential oils are obtain from every part of plant like stem, root, leaves, flowers, seed, branches etc. And these essential oils are used in the preparation of drugs, cosmetics and perfumes.
Holi Tulsi Plant
Ocimum Basillicum means Tulsi is an aromatic plant. Ocimum Basillicum is used to obtain essential oil useful for different application. This oil evaporates within 24 hours after applying it to our body. This essential oil helps in cure of digestion problem, strained muscles, headaches and nervous breakdowns. Due to its good medicinal properties and aroma its demand is very high in many countries. A person or company can build a small or large scale industry for the extraction of essential oil from Ocimum Basillicum (Tulsi).

Top 10 General qualitative properties of Ocimum Basillicum essential oil are given below-

essential oil extraction equipment photo1.  Appearance : Transparent fluid
2.  Color : Pale yellow
3.  Fragrance : Ocimum Basillicum’s distinctive flavor and fragrance
4.  Refractive Index on 20°C : 1.51200 to1.51900
5.  Specific Gravity on 25°C : 0.95200 to 0.97300
6.  Optical gyration on 25°C : [-] 8.85º to [-] 11.85º
7.  Well mixed with Hydroxycitronellal
8.  Insoluble in water
9.  Dissolved in paraffin oil

How to obtain oil from holi Tulsi plant?

The extraction of essential oil by steam distillation of ocimum basillicum (Tulsi) is a solid-liquid extraction process. This process completes in following steps-
Flow diagram of steam distilatillation
1.  Collect plant material and dry it if required.
2.  Fill this plant material in distillation vessel.
3.  Add water or solvent (like Ethanol, n-Hexane) in distillation vessel.
4.  Heat the mixture in well-equipped distillation vessel in control environment and controlled temperature, then
5.  Diffusion of essential oil from inside of solid material of plant to its surface occurs, then
6.  Transfer of mass from surface of plant solid material to surrounding liquid occurs, then
7.  This liquid contains essential oil which is obtained by reverse cooler.
8.  Then the collection of above liquid obtained from reverse cooler is put to stand for some time then essential oil come over water, then
9.  We perform layer separation to separate out essential oil from water, then
10.              Store this essential oil in dark, closed vessel for future use.
how to obtain Essential oil by steam distillation ?
The experimental results proves that yield of essential oil of Tulsi (Ocimum-Basillicum)  from only leaves of plant is slightly higher than from the mixture of leaves and stems (means plant crush).

GATE Syllabus for Chemistry (CY)


Structure:Quantum theory: principles and techniques; applications to a particle in a box, harmonic oscillator, rigid rotor and hydrogen atom; valence bond and molecular orbital theories, Hückel approximation; approximate techniques: variation and perturbation; symmetry, point groups; rotational, vibrational, electronic, NMR, and ESR spectroscopy
Equilibrium: Kinetic theory of gases; First law of thermodynamics, heat, energy, and work; second law of thermodynamics and entropy; third law and absolute entropy; free energy; partial molar quantities; ideal and non-ideal solutions; phase transformation: phase rule and phase diagrams – one, two, and three component systems; activity, activity coefficient, fugacity, and fugacity coefficient; chemical equilibrium, response of chemical equilibrium to temperature and pressure; colligative properties; Debye-Hückel theory; thermodynamics of electrochemical cells; standard electrode potentials: applications – corrosion and energy conversion; molecular partition function (translational, rotational, vibrational, and electronic).
Kinetics: Rates of chemical reactions, temperature dependence of chemical reactions; elementary, consecutive, and parallel reactions; steady state approximation; theories of reaction rates – collision and transition state theory, relaxation kinetics, kinetics of photochemical reactions and free radical polymerization, homogeneous catalysis, adsorption isotherms and heterogeneous catalysis. 


Main group elements: General characteristics, allotropes, structure and reactions of simple and industrially important compounds: boranes, carboranes, silicones, silicates, boron nitride, borazines and phosphazenes. Hydrides, oxides and oxoacids of pnictogens (N, P), chalcogens (S, Se & Te) and halogens, xenon compounds, pseudo halogens and interhalogen compounds. Shapes of molecules and hard- soft acid base concept. Structure and Bonding (VBT) of B, Al, Si, N, P, S, Cl compounds. Allotropes of carbon: graphite, diamond, C60. Synthesis and reactivity of inorganic polymers of Si and P.
Transition Elements: General characteristics of d and f block elements; coordination chemistry: structure and isomerism, stability, theories of metal- ligand bonding (CFT and LFT), mechanisms of substitution and electron transfer reactions of coordination complexes. Electronic spectra and magnetic properties of transition metal complexes, lanthanides and actinides. Metal carbonyls, metal- metal bonds and metal atom clusters, metallocenes; transition metal complexes with bonds to hydrogen, alkyls, alkenes and arenes; metal carbenes; use of organometallic compounds as catalysts in organic synthesis. Bioinorganic chemistry of Na, K. Mg, Ca, Fe, Co, Zn, Cu and Mo.
Solids:Crystal systems and lattices, miller planes, crystal packing, crystal defects; Bragg’s Law, ionic crystals, band theory, metals and semiconductors, Different structures of AX, AX2, ABX3 compounds, spinels.
Instrumental methods of analysis: Atomic absorption and emission spectroscopy including ICP-AES, UV- visible spectrophotometry, NMR,
mass, Mossbauer spectroscopy (Fe and Sn), ESR spectroscopy, chromatography including GC and HPLC and electro-analytical methods
(Coulometry, cyclic voltammetry, polarography– amperometry, and ion selective electrodes). 


Stereochemistry: Chirality of organic molecules with or without chiral centres. Specification of configuration in compounds having one or more stereogeniccentres. Enantiotopic and diastereotopic atoms, groups and faces. Stereoselective and stereospecific synthesis. Conformational analysis of acyclic and cyclic compounds. Geometrical isomerism. Configurational and conformational effects on reactivity and selectivity/specificity.
Reaction mechanism: Methods of determining reaction mechanisms. Nucleophilic and electrophilic substitutions and additions to multiple bonds. Elimination reactions. Reactive intermediates- carbocations, carbanions, carbenes, nitrenes, arynes, free radicals. Molecular rearrangements involving electron deficient atoms.
Organic synthesis: Synthesis, reactions, mechanisms and selectivity involving the following-alkenes, alkynes, arenes, alcohols, phenols, aldehydes, ketones, carboxylic acids and their derivatives, halides, nitro compounds and amines. Use of compounds of Mg, Li, Cu, B and Si inorganic synthesis. Concepts in multistep synthesis- retrosynthetic analysis, disconnections, synthons, synthetic equivalents, reactivity umpolung, selectivity, protection and deprotection of functional groups.
Pericyclic reactions: Electrocyclic, cycloaddition and sigmatropic reactions. Orbital correlation, FMO and PMO treatments.
Photochemistry: Basic principles. Photochemistry of alkenes, carbonyl compounds, and arenes. Photooxidation and photoreduction. Di-π- methane rearrangement, Barton reaction.
Heterocyclic compounds: Structure, preparation, properties and reactions of furan, pyrrole, thiophene, pyridine, indole and their derivatives.
Biomolecules: Structure, properties and reactions of mono- and di-saccharides, physicochemical properties of amino acids, chemical synthesis of peptides, structural features of proteins, nucleic-acids, steroids, terpenoids, carotenoids, and alkaloids.
Spectroscopy: Principles and applications of UV-visible, IR, NMR and Mass spectrometry in the determination of structures of organic molecules.

Pattern for Single Paper MCQ test- NET Chemistry

UGC NET Chemistry (CY) Exam Patter

  • The MCQ test paper of chemistry shall carry maximum of 200 marks.
  • This exam shall be for duration of 3hrs.
  • The question paper shall be divided in three parts i.e.
    Part 'A' , Part 'B', Part 'C'
Part wise description of paper
  • Part 'A' shall be common to all subjects. This part shall be a test containing a maximum of 20 questions of General Aptitude. The candidates shall be required to answer any 15 questions of two marks each. The total marks allocated to this section shall be 30 out of 200
  • Part 'B' shall   contain subject-related conventional MCQs. The total marks allocated to this section shall be 70 out of 200. The maximum number of questions to be attempted shall be in the range of 20-35. 
  • Part 'C' shall contain higher value questions that may test the candidate's knowledge of scientific concepts and/or application of the scientific concepts. The questions shall be of analytical nature where a candidate is expected to apply the scientific knowledge to arrive at the solution to the given scientific problem.  The total marks allocated to this section shall be 100 out of 200.
  • Negative marking for wrong answers. 



CSIR-UGC National Eligibility Test (NET) for Junior Research

Fellowship and Lecturer-ship





Physical Chemistry :

1. Basic principles and applications

of quantum mechanics – hydrogen atom,
angular momentum.
2. Variational and perturbational methods.
3. Basics of atomic structure, electronic
configuration, shapes of orbitals, hydrogen
atom spectra.
4. Theoretical treatment of atomic
structures and chemical bonding.
5. Chemical applications of group theory.
6. Basic principles and application of
spectroscopy – rotational, vibrational,
electronic, Raman, ESR, NMR.
7. Chemical thermodynamics.
8. Phase equilibria.
9. Statistical thermodynamics.
10. Chemical equilibria.
11. Electrochemistry – Nernst equation, elect
rode kinetics, electrical double layer,
Debye-Hückel theory.
12. Chemical kinetics – empirical rate laws,
Arrhenius equation, theories of reaction
rates, determination of reaction mech
anisms, experimental techniques
for fast reactions.
13. Concepts of catalysis.
14. Polymer chemistry. Molecular weights
and their determinations. Kinetics of
chain polymerization.
15. Solids - structural classification of
binary and ternary compounds, diffraction
techniques, bonding, thermal, elect
rical and magnetic properties
16. Collids and surface phenomena.
17. Data analysis.

Inorganic Chemistry :

1. Chemical periodicity

2. Structure and bonding in homo- and heter
onuclear molecules, including shapes of
3. Concepts of acids and bases.
4. Chemistry of the main group elements
and their compounds. A
llotropy, synthesis,
bonding and structure.
5. Chemistry of transition elements and
coordination compounds – bonding theories,
spectral and magnetic properties, reaction mechanisms.
6. Inner transition elements – spectral
and magnetic properties, analytical
7. Organometallic compounds - synthesis,
bonding and structure, and reactivity.
Organometallics in homogenous catalysis.
8. Cages and metal clusters.
9. Analytical chemistry- separation
techniques. Spectroscopic electro- and
thermoanalytical methods.
10. Bioinorganic chemistry – photosystems, porphyrines, metalloenzymes, oxygen
transport, electron- transfer
reactions, nitrogen fixation.
11. Physical characterisation of inorga
nic compounds by IR, Raman, NMR, EPR,
Mössbauer, UV-, NQR, MS, electron spect
roscopy and microscopic techniques.
12. Nuclear chemistry – nuclear reactions
, fission and fusion, radio-analytical
techniques and ac
tivation analysis.

Organic Chemistry :

1. IUPAC nomenclature of organic compounds.

2. Principles of stereochemistry, conforma
tional analysis, isomerism and chirality.
3. Reactive intermediates and
organic reaction mechanisms.
4. Concepts of aromaticity.
5. Pericyclic reactions.
6. Named reactions.
7. Transformations and rearrangements.
8. Principles and applications of orga
nic photochemistry. Free radical reactions.
9. Reactions involving nucle
ophotic carbon intermediates.
10. Oxidation and reduction of functional groups.
11. Common reagents (organic, inorganic a
nd organometallic) in organic synthesis.
12. Chemistry of natural products such as
steroids, alkaloids, terpenes, peptides,
carbohydrates, nucleic acids and lipids.
13. Selective organic transformations
– chemoselectivity, regioselectivity,
stereoselectivity, enantiosele
ctivity. Protecting groups.
14. Chemistry of aromatic and a
liphatic heterocy
clic compounds.
15. Physical characterisation of organic compounds by IR, UV-, MS, and NMR.

Interdisciplinary topics :

1. Chemistry in nanoscience and technology.

2. Catalysis and green chemistry.
3. Medicinal chemistry.
4. Supramolecular chemistry.
5. Environmental chemistry.

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