Tuesday, June 1, 2010

BASICS FOR THE CHEMICAL TANKERMAN -- CAPT AJIT VADAKAYIL






FOR CHEMICAL TANKER DECK OFFICERS AND SAILORS --


A parcel chemical man must know the basics.  Or he cannot run a SAFE and efficient chemical parcel tanker.  
On Chemical tankers we have lot of  " Shakespeares "  who do NOT know English alphabets A B C D -- etc--  it is so pathetic .  The Superintendents and Supercargoes who direct you from ashore are even worse pretenders  --
BE SAFE -- Ignorance is NOT bliss,  in this dangerous field.


SLOG LESS -  Most of the time spent in tank cleaning is fruitless--
READ ON--
Everything you see  on this planet is made out of 118 atoms or elements.  Atomic number 118 belongs to Ununoctium.



Take a pure silver coin and keep splitting it into two halves and discard one of them . Keep repeating and soon enough you will not be able to see it visually but only under a sensitive microscope. Continue dividing and finally you have a piece of silver which cannot be divided any more . This piece is the atom or element we are referring to.


Whatever you see around you unless it is an extra-terrestrial object like a Shiva lingum    ( this is a black stone found in Indian temples  ) is made out of a combination of these atoms.


Everything made by combining these atoms tend to go back to its mother state as a natural tendency, on passage of time . That however does not give you license to flout Marpol regulations or throw plastics overboard.

All elements heavier than lead are unstable and radioactive

An inorganic chemical does not have a carbon atom.   It is made of a combination of the remaining 118 atoms or elements.  These atoms are joined together by electrovalent bonds giving rise to simple and small number of compounds.   Inorganic reactions are ionic and fast.

An organic chemical must contain the carbon  atom  as a rule.  Carbon is combined with atoms of hydrogen, oxygen, nitrogen, sulphur, phosphorous etc .  The carbon atoms are joined together by covalent bonds to form long chains or rings thus giving rise to a large number of complex compounds we carry on parcel chemical tankers.  Reactions are non ionic and slow. Hydrocarbon gases have upto 4 carbon atoms.  Liquids have 5 to 19 and gases have more  than 20 carbon atoms.


In the middle of the atom is the nucleus.  The nucleus contains protons (+) and neutrons. Revolving around the nucleus in elliptical orbits are  electrons.(-). The only reason all 118 atoms are different from each other is because the count of protons , neutrons and electrons are different. The number of electrons and protons of an atom are equal.  For example the carbon atom has 6 electrons and 6 protons. The number may be equal but the proton mass is 1832 times that of an electron. Copper has 29 of each. Silver has 47 of each..  The atomic number of an element is the number of protons in the nucleus. Carbon’s atomic number is 6.


An acid is a proton donor, a base is a proton acceptor.

Acids are neutralized by reaction with bases and vice versa. 




Organic acids are flammable. They react with metals to give off Hydrogen.


Organic bases are flammable, and many are reducing agents. A base which is soluble in water is called an Alkali.

The model of the atom is similar to our solar system ( only for understanding purposes). Nucleus is the sun, electrons are planets. The atom is thus mostly empty space as the planets are far from the sun. Electrons can exist as part of an atom or in the free state. The science of electronics was possible by the ability of a heated metal cathode to emit a continious stream of electrons into a electron tube.


A molecule is a particle made out of 2 or more atoms.  An electrical bond  hold atoms together in a molecule.  Benzene is a flat molecule with  Carbon/ Hydrogen lying in the same plane at 120 degrees. Hydrocarbon molecules have Carbon and Hydrogen atoms in various arrangements.

Many chemicals are reactive with themselves. Such reaction may result in the formation of larger molecules. Polymerisation, (like crazy glue) or the disintegration of molecules ( decomposition). Polymerisation happens molecules which link together into a larger unit containing anything from 2 to thousands of molecules .


Capillarity is the attraction between the molecules which results in the rise of a liquid in small tubes.

Brownian movement is the continious zig zag movemenbt of particles in a colloidal suspension, caused by impact of molecules of liquid on the colloidal particles.

The plasma cutter we use for cutting stainless steel can develop temperatures upto 28000 deg C.  Plasma results when a gas is  heated to heated to a high temperature and changes into positive ions, neutral atoms and negative electrons and is generally considered the fourth state of matter—the other 3 being solids, liquids and gases.


Protons have positive charge, electrons have negative charge of equal strength and neutrons have no charge at all.  Since the number of electrons and protons are the same the atom has no resultant charge and is neutral.

The protons and neutrons are held together very tightly in the nuclues. But the outer orbital electrons are held very loosely. They can jump from one atom to another. It is also possible to shift electrons from one atom to another.  The atom which loses one electron has  one excess proton as a result in the tight nucleus and thus gets unbalanced. Such an atom is called a positive ion.

The atom which receives an excess electron is also unbalanced and is called a negative ion. Positive and negative ions are thus all the time trying to give up or receive an electron which they need. There is a mutual attraction between them like between a boy and a girl searching for a soulmate.  When a postive and negative ion are kept apart there is static electricity. When they are brought close without touching the excess electrons from  a negative ion jumps across till both become neutral accompanied by light and sound --like lightning and thunder.




When you rub a plastic scale on your hand the skin loses electrons. Air, skin, glass, hair, nylon wool etc lose electrons.  On the contrary polyster rubber, pvc , teflon etc easily absorb electrons. The more the rubbing, the larger the charge. It is not the friction which does this. Rather it is the increase in contact area.  Again, an atom which has gained or lost electrons is said to be ionised. Now you have a general idea what is DI ( de ionised )water which you so gleefully spray on your tank bulkheads.

An ion often has entirely different properties from the atom from which it was formed. Ion formation increases the bp and reduces the freezing point.

Some materials hold their electrons very tightly. Electrons are not allowed to wander . These materials are called insulators.  Examples are glass , plastic,  dry air etc. 


Some materials on the contrary have electrons held very loosely which wander through very easily. These materals are called conductors.  Examples are metals.   Free electrons wander through a metal conductor aimlessly, but remember  the conductor as a whole remains electrically neutral. A good conductor has lot of  free electrons in the outer orbit.

The flow of electrons in a conductor is random and not to any certain direction.  6.28  x 10 raised to 18  electrons per second is thus called one ampere. If you visualise a water tank with a drain cock and tube at the bottom—the level of water in tank is  potential difference in volts (E) , the thickness of tube is resistance in ohms (R), and the quantity of water flow through the tube is current amperes(I). 


The basic electrical formula we all know is--
  I =E / R.
So then what kills amperes or volts?  Think about it !! 

0.100– 0.200  Amperes (death) this range generally causes Fibrillation of the heart. when the heart is in this condition, it vibrates at a fast rate like a “quiver” and
ceases to pump blood to the rest of the body.
0.060– 0.100 A  (extreme difficulty in breathing)
0.030– 0.040 A (muscular paralysis)
0.020– 0.030 A (unable to let go of the circuit)
0.010– 0.020 A (very painful)

Like charges repel and unlike charges attract. But a charged object can also attract something which is neutral.

When you walkdown a ships alleyway stairway in absolute darkness on a cold dry day and slide yor hand on the plastic sheath of the handrail you can actually see electrons jumping from your finger tips to the metal frame accompanied by tiny shocks. When the air is humid the water in the air removes free electrons from your body and thus it cannot build up a charge which can give a nasty shock. So then what is a spark. It is a sudden rush of electrons. Having said this what is electricity? It is a flow of free electrons of the metal wire. 


AC supply of 50 Hertz or Cycles per second becomes negative 50 times , positive 50 times and zero 100 times every second. The filament of an electric bulb lights up because it does not get the time to cool down. An incendive spark is what can cause an explosion. This is the reason why on chemical tankers who carry static accumulator chemicals the bottom one foot of all all railings on deck, the paint is stripped off to bare metal.

Shake up a metal can containing Toluene or Kerosene and bring it very close to a metal surface in a dark room. You can see the  jumping electrons for yourself --like arc welding.

The reason why the human body conducts electricity is due to salt in your blood and cells.

A positive ion is called a cation and negative ion is called anion. 


A non bonded projecting object can become a potential electrode of spark promoter collecting the charge from the liquid.when it is close  enough to an earth the spark promoter instantaneously releases its charge in an arc ( spark ). When a charged liquid flows into the ships tank it attracts a charge of same size but of opposite polarity to the inner bulkheads of tank.

Charge relaxation depends on the conductivity of the liquid.. There can be high voltage at the surface of the liquid called surface voltage. At high surface voltage with sufficient potential difference a spark can jump to the liquid surface. Such a phenomenon is called brush incendive discharge and can cause an explosion., which causes ignorant souls to scratch their collective heads.


On chemical tankers you will find that protruding objects like high level alarm and  fixed tank cleaning machines inside the cargo tank are properly earthed. A Toluene deck tank is also securely earthed—your ship can fail a risk assessment inspection if not.

Even to run a proper engine room you need to know about static electricity charges. With modern engines being fitted with nominal 10 micron heavy oil fine filters ,without homogenisers –to keep colloids apart which have been coagulated by the centrifuging action of purifier. .

  
Modern sewage treatment plants use cataphoresis.  Sewage water contains colloids which carry electric charge and do not settle down easily. Thses particles can be removed by cataphoresis in which sewage water is passed through a tunnel fitted with metallic electrodes maintained at high potential difference.the charged particles migrate to oppositely charged electrodes and get neutralised and gets coagulated and settle down.. The deposited water is used as manure and clean water for irrigation or even drinking.


An ionic bond results from the transfer of electron ( structural unit is ions ) while a covalent bond results from the sharing of electrons ( structural unit is molecules ).

A salt NaCl crystal is extremely strong and rigid. A sodium Na ion is equally attracted to 6 chloride Cl ions. These powerful interionic forces are overcome only at its melting point of 801 degree centigrade.  NaCl is an ionic compound which has equal number of sodium cations and chloride anions. 


Water is a good solvent for salt . It has a high di-electric constant or relative permitivity. ( 81 --it has no units ). This means the force of attraction between ions is 81 times less in water than in a vacuum and this allows them to separate. High di-electric constant is equivalent to high insulating properties to lower the attraction between the oppositely charged ions once they are solvated. Water solvates both cations and anions.  When you do a chloride wall wash test rememer that a pinch of salt put in methanol remains there , and water is the best solvent.


When a solid or liquid dissolves the structural unit ions or molecules become separated from each other and the spaces in between become occupied by solvent molecules.

As per the Bronsted –Lowry theory ---an acid contains Hydrogen which when dissolved in water become disassociated and generates Hydrogen ions.  An acid is  termed as a  substance that gives up a proton.  The ease with which an acid loses a proton is known as its strength .  Sulphuric acid and Hydrochloric acids are strong acids since they tend to give up a proton very readily.   A proton is an acid because it is deficient in electrons and need an electron pair to complete its valence shell.  Acids give hydrogen ions in aqueous solution.  Acids react with metals and give off hydrogen. Acids have sour taste.

Some substances have more than one proton that can be given to a base. Such acids are known as polyprotic acids. Sulphuric acid is an example of a polyprotic acid, since it can lose two protons to the base water ( in other words it is a diprotic acid in two ionisation stages ).

As per the Bronsted –Lowry theory --a base is a substance that accepts a proton. The ease with which a base takes up a proton is called strength of a base. Base gives hydroxide ions in an aqueous solution. Bases have bitter taste and are slippery to touch.

It is there fore commonsense that an acid will react with a base by the transfer of a proton from the acid to the base.

When an acid and a base react to from salt and water, the process is known as neutralisation.

Some substances can act both as acids ( by losing an H+ion ) and as bases ( by gaining an H+ ion ). Such substances are known as amphiprotic substances or ampholytes. Water is such an example.

Buffer is a solution containing both a weak acid and its conjugate weak base. The weak acid becomes a buffer when alkali is added and vice versa.


Solute molecules and ions do not exist in solution as naked particles.—they are solvated. Clinging to each dissolved particle is a cluster of solvent molecules held there by bonds. It was formation of these bonds that provided the energy to break the bonds that held solute particles together. The very fact that dissolution has taken place show that new bonds have taken the place of old ones.

According to the laws of electrostatics the stability of a charged system is increased by dispersal of charge.. Dispersal of charge by solvation  tends to stabilise  cations and anions . Water is the most common solvent as it can act as both an acid and a base.  Solvents which have a greater tendency to accept a proton is called protophillic eg water, alchohol.  Solvents which have a greater tendency to donate a proton is called protogenic eg water, acetic acid. 


Most of the organic substances ( non polar ) dissolve in one another but not in water ( polar ).  Similarly inorganic substances (polar ) are generally soluble in water and other polar solvents.  




Most solids become more soluble with increase of temperature. The solvent must do more than simply being a broker to bring different molecules together so that they can react with each other. The solvent is involved in the reaction which takes place.

NaCl electrolyte is completely disassociated in solution. The tendency of ions to migrate and thus conduct electricity is retarded by the electrostatic attraction between cations and anions and also between ions and the solvent. As the concentration of this solution is increased the retarding effect is increased. So a fixed amount of NaCl is a better conductor when dissolved in a large amount of water because ions are further apart and exert less attraction upon one another and upon the solvent molecules.




Chemical behavior is determined by molecular structure.  Crosslinking in rubber is brought about by vulcanising—heating with sulphur—which cause formation of sulphur bridges between molecules.

Two molecules with the same molecular formula but different constitutional formulas are called isomers.

Chemical formulas are empirical, molecular, structural and electronic.


C2H5OH / molecular for  ethanol


Oxidation can be termed as removal of hydrogen atom or addition of oxygen atom

Reduction can be termed as addition of hydrogen atom or removal of oxygen atom

An atom/ ion/ molecule that donates electrons is called reducing agent while those which accepts electrons is called an oxidising agent.

Thus in corrosion a metal is oxidised by loss of electrons to oxygen and formation of oxides.

A substance that ionises in water to produce ions other than h+ and oh- is called a salt. Salt is produced by neutralisation.

Diffusion, is the flow of matter from a higher concentration to a lower concentration, resulting in an even distribution. the rate of diffusion is proportional to the cross-sectional area and to the gradient of concentration, temperature, or charge (when the gradient is small). diffusion is a molecular process, depending solely on the random motions of individual molecules. The rate of diffusion of matter is therefore directly proportional to the average velocity of the molecules—the diffusion coefficients of chemicals are known.

No lather can be produced unless all Calcium and Magnesium ions ( cations ) have been precipitated. Temporary hardness is removed by boiling for 15 min. The bicarbonates of Calcium and Magnesium will decompose to insoluble carbonates which settle as precipitate.


Permanent hardness is removed by adding washing soda. Na2Co3 10 H2O. So hardness is defined as concentration of Cal/ Mag cations in terms of Calcium Carbonate.  Concentration is measured in degrees hardness. There are many units like American/ English/ French/ German hardness etc.
Hardness units: 1 ppm = 1 mg/l = 0.1 Fr = 0.07 Cl = 0.02 Meq/l
Fr = French   Cl = Clarke   Meq = milli equivalent





Good fresh water has a hardness of 2  while seawater has a hardness of 6800 mg/l


Seawater contains a lot of calcium/ magnesium and therefore has high water hardness. Some products like fatty acids and vegetable oils with a high free fatty acid content will formate white sticky residues ( calcium and magnesium soaps ) if they were cleaned with a water of a high water hardness ( eg. Sea water)

Soap is dispersed in spherical clusters called miscelles each of which may contain hundreds of soap molecules. A soap molecule has a polar end which is water soluble (hydrophilic) and a and a non polar end which is not water soluble (hydrophobic ).


The non polar HC chains dissolve in each other. The polar groups dissolve in water.  Similarly charged miscelles repel each other and prevent oil droplets from coalescing. A stable emulsion of oil and water forms and can be removed easily from the surface being cleaned. Hardwater contains Cal/ Mag salts which react with soap to form insoluble Cal/ Mag Carboxylates ( ring in the bath tub which always got your non-chemical chambermaid  disgusted with your personal hygiene ).


C12 –C18 alcohols are used in enormous quantities to make detergentsTenside in a detergent wraps up a particle and prevents it from redepositing.  One end of the tenside molecule has affinity to water and the other is repellent to water.  Emulsifier has a water seeking end and a oil seeking end. Emulsification does not involve chemical change. It just suspends particles of one product with another which gives rise to a milky appearance of solution.


Synthetic detergent molecules have a non polar end which is oil soluble and a polar end which is water soluble. The most widely used detergents are sodium salts of Alkyl Benzene Sulphonic acids. 




Soft biodegradable detergents are Alkyl Suphates, Ethoxylates and their Sulphates and Alky Benzene Sulphonates.  Sulphates and Sulphonates retain their efficiency in hard water since their correpsonding Cal/ Mag salts are soluble.  Being salts of strong acids they yield neutral solutions in contrast with soaps which being salts of weak acids yield slightly alkaline solutions.

To dissolve an ionic compound the solvent must be highly polar. In addition it must have a high dielectric constant. Ie-- it must be a good insulator to lower the attraction between oppositely charged ions once they are solvated. 


There are other liquids which have very large dipole moments and high dielectric constants and yet are very poor solvents for ionic compounds. What is needed is solvating power---the ability to form strong bonds to dissolved ions. Water owes a large part of its special solvating power to its OH- group. It solvates cations strongly through the unshared pairs on oxygen. It solvates anions strongly through hydrogen bonding. 


Methanol resembles water in having an OH- group. It is not surprising that it too dissolves ionic compounds, However it is inferior to water as it is less polar.  This is the reason why water must be added into the methanol wash before adding Silver Nitrate for the Chloride test.

Solvents such as water and methanol are called protic solvents.----solvents containing Hydrogen that is attached to oxygen or nitrogen and hence is acidic enough to form Hydrogen bonds. Other protic solvents solvate ions in the same way that water does. –cations through unshared pairs and anions through hydrogen bonding.

Recent years have seen the development and wide spread use of polar aprotic solvents---solvents with moderately high dielectric constants which do not contain acidic hydrogen eg DMSO/ DMF/ HMPT.  They dissolve ionic compounds but in a different way from protic solvents.. They cannot form hydrogen bonds to anions. Aprotic solvents dissolve ionic compounds chiefly through their solvation of cations. Water dissolves ionic compounds very well but is a poor solvent for most organic compounds. Non polar solvents like ether are good solvents for organic compounds but very poor solvents for inorganic salts. Methanol can be used for this.  Aprotic solvents through their lipophilic (oil loving )portions dissolve organic compounds.they also dissolve inorganic compounds through solvation of cations. Aprotic solvents work at room temp efficiently.


DMSO:-

A change to an aprotic solvent can increase the tankcleaning reaction rate as much to a million fold.  Among protic solvents, ionising power is highest for solvents that form the strongest hydrogen bonds ie the solvents with the most acidic Hydrogens. Aprotic solvents dissolve ionic reagents chiefly through their bonding to the cation. This leaves the anion free and highly reactive.

WATER SOLUBLITY

Soluble organic chemicals
Insoluble organic chemicals
      Organic salts
      Saturated hydrocarbons
      Alcohols
      Unsaturated hydrocarbons
      Esters
      Aromatic hydrocarbons
      Ethers
      Alkyl halides
      Acids
      Aryl halides
      Amines
 
      Nitriles
 
      Amides
 
      Ketones
 
      Aldehydes

 
Position of functional group, branching, and the compactness of the molecule will affect solubility
Functional group toward center of molecule  means increased water solubility
Increase in the number of branches means increased water solubility
More compact molecular shape means increased water solubility

Few notable general properties of chemical groups:--

Non oxidising mineral acids:
Ex: Phosphoric, Hydrochloric acid, Ferric chloride solution

Organic acids:
Divided to Carboxylic and Dicarboxylic


Carboxylic:
Aliphatic acids are , Lactic, Formic
Aromatic acids are, Benzoic, Salicylic

Dicarboxylic:
Oxalic, Phthalic, Sebacic, Adipic

Caustics:
Ex: Caustic potash, Caustic soda, Calcium hypochlorite, Sodium carbonate, Sodium Hydrosulphide, Sodium nitrite

Ammonia:
Ex: anything starting with Ammonia.
Ammonium nitrate, Ammonium hydroxide

Amines:
Ex: anything ending with ine
Substances derived from Ammonia
Highly toxic
Low FP
Soluble in water.
React vigorously with acids
Simple amines have fishy smell
VD>1 ( except Ammonia )
Simple amines have fishy smell


Aromatic Amine:
Ex: anything ending with line or dine
Aniline, pyridine

Amide:
Ex: all ending in amide
Acrylamide, Formamide, Acetamide

Organic anhydride:
Ex: all ending with Anhydride
Acetic anhydride, Maleic anhydride, Propionic anyhdride
May be toxic
May react violently with water giving off heat

Isocyanates:
Ex: all ending in Isocyanate
TDI, MDI
Toxic
Water reactive

Vinyl acetate:
Ex: all starting with Vinyl
Vinyl toluene, Vinyl acetate

Acrylates:
Ex: all ending in Acrylate
Ethyl acrylate, Methyl acrylate
Inhibited
Pungent odour

Substituted allyls:
Ex: Acrylonitrile, Allyl alcohol, Dichloropropene, Allyl chloride
Polymerise

Alkylene oxides:
Ex: Propylene oxide is the only one for chemical tankers
Very wide flammable range
Burns violently
Very difficult to extinguish by smothering due to O2 content
Inert tank
Keep cool

Ketones:
Ex: Acetone, Cyclohexanone, Camphor oil , Epoxy resin, all ketones
Low FP
Soluble in water
Low toxicity
Low reactivity
Narcotic
VD>1

Aldehydes:
Ex: all ending in Aldehyde or al ( Butanal, Furfural, Propanal  ),Acetaldehyde, Pentyl aldeyde, Formaldehyde

Low FP, except for Benzaldehyde
Oxidises in air and forms unstable peroxides which readily explode
Very reactive
Moderately toxic
Vapours irritate
Soluble in water/ alcohol
Some will polymerise
Characteristically pungent smell
Variable densities

Alcohols/ glycols:
Ex: all ols and cols
Butyl alcohol, Cyclohexanol, Ethyl alcohol, Ethylene glycol, Heptanol, Methanol, Molasses, Tallow fatty alcohol
Alcohol solubility in water decreases as the number of carbon atoms increases
BP and SG increase with increasing molecular mass.
Alcohols have low flash points and hence flammable/ glycols have high FP
Most alcohols are toxic , Glycols moderate
Relative VD of alcohols are > 1

Phenols/ Cresols:

Ex: Benzyl alcohol, Creosote, Cresols, Phenol, Dodecyl Phenol, Nonyl Phenol, Xylenol
Low MP.
Not very soluble in water.
Toxic/ corrosive

Olefins:
Ex: all ending in ene
Butadiene, Dipentene, Ethylene, Hexene, Natural latex, alpha Methyl Styrene, Nonene, Pentene, Styrene, Turpentine

Paraffins:
All ending in ane
C6 to c9 Alkanes, n Alkanes>c10, Cyclohexane, Pentane, Paraffin

Aromatic hydrocarbons:
Ex: Benzene, Toluene, Xylene, Cumene, Dodecyl Benzene, Naphtalene
Flammable,
Sweetsmelling,
burns with smoky flames,
Stable,
Toxic,
Anaesthetic.


Misc HC mixtures:
Ex: distillates, drilling muds, CPP, Diesel oil, Lub oils, Petroleum wax, White spirit, Coal tar, Heartcut distillate, Linseed, Pine oil

Esters:
Veg/ animal/ fish oils, Phthalates,  Ethylene Glycol Acetates, Di Ethylene Glycols, the list is very large
Insoluble in water
Highly flammable
Non toxic
Neutral substance reacts with water to give acid plus alcohol
Volatile
Pleasant odour
Not very reactive
Colourless

Vinyl halides:
Ex: Vinyl chloride, Vinylidine Flouride
Most are gases at ambient temperatures

Halogenated HC
Ex: will have Chlor on the name
CTC, Chlorinated Paraffins, EDC, Methyl chloride, Trichloroethane
Non biodegradable
Insoluble in water
Toxic
Low flammability
Decomposes when heated to give toxic gases
Some quench flames
Stable
VD>1

Nitriles:
Ex: all ending with Nitrile ( Acrylonitrile )
Very toxic
Low FP
Slightly soluble in water
May react violently with acids, alkalies and oxidising agents.
VD>1

Glycol ether:
Will have glycol ether in the name
Ex: Cellosolve , Poly Ethylene Glycol, Ethylene Glycol MonoButyl ether
Flammable variable FP
Harmful to health
Soluble in water
Vd>1


Ethers:
Butyl ether, Ethyl ether, MTBE
Low FP, hence flammable.
All are toxic with narcotic , anesthetic effect
Flammable
Oxide in air to form peroxides which are potentially explosive

Nitrocompounds:
Ex: starts with nitro
Toxic, especially when on fire

Misc water solutions:
Ex: Urea, Calcium Bromide, Clay slurry, Corn syrup, Drilling brine , Latex synthetic, Lignin liquor, treated sewage sludge
Soluble in water
Do not keep adjacent to cargoes which react with water
Properties of solution might be different from those of the pure product

Acids:
Reacts with metals to give of hydrogen
Yields hydrogen ions when dissolved in water
Neutralised by reaction with bases
Organic acids are flammable
Can be an oxidising agent or reducing agent.
Reacts with human tissue

Bases:
Compounds which are able to combine with hydrogen ions.
Reacts with human tissue.
Neutralise acids
Organic bases are flammable
A base which is soluble in water is called an alkali




Hydrocarbons:


Hydrocarbons are divided into--
1) Aliphatic
Chain like skeleton of C atoms, not arranged in ring structure, but open chains ( ethane )


2) Aromatic
( Rings of carbon atoms , Benzene, Toluene, Xylene ), sweetsmelling, Flammable, burn with smoky flames, stable, toxic, anaesthetic.


Aliphatic HC are further divide into—

1) Alkanes
Molecular formula: Cn H2n+2   saturated HC containing single bond.  No action on Potassium Permanganate. Also called Paraffin.
Ex: all ending in ane  --Pentane, Butane, Hexane
Ch4/ Methane
C2h6/ Ethane
C3h8/ Propane
C4h10/ Butane
C5h12/ Pentane
C6h14/ Hexane

Thus when n=8, ( 2n+2)=18 and the Alkane is C8 H18 , it is called octane.
It is one of the Alkanes in petrol.




Petroleum fractions and molecular composition of Alkanes present:
Gas/ C1 to C4
C5 to C7/ Petrol Ether
C5 to C9/ Motor Spirit
C9 to C10/ Naphtha
C10 to C16/ Kerosene
C10 to C18/ DO
C17 to C30/ HO
C15 to C50/ LO

2) Alkenes
Mol formula Cn H2n    unsaturated HC containing double bond.  Decolourises Potassium Permanganate
Ex: all ending in ene
Ethylene, Propelene, Pentene, Hexene


3) Alkynes
MF: Cn H2n–2    unsaturated HC containing tripe bond



4) Cyclic Aliphatic
All starting with Cyclo and ending with ane/ ene

Number of carbon atoms in HC:
1/ Meth
2/ Eth
3/ Prop
4/ But
5/ Pent
6/Hex
7/Hept
8/Oct


Proforma:  SG/ BP/ MP
Methane/ 0.42/ -160C/ -186C
Ethane/ 0.45/ -93C/ -172C
Propane/ 0.54/ -40C/ -814C
Butane/ 0.60/ 1C/ 135C
Pentane/ 0.63/ 36C/ -130C

The smaller saturated HC methane, ethane , propane and butane are all colourless and odourless liquefied gases.  They are all flammable and will burn in air to form CO2 and water.

HC contain only carbon and hydrogen atoms.
4 carbon atoms in molecule/ gases at ambient temp / pressure ( propane )
5 to 20 carbon atoms/ liquid at ambient conditions  ( octane )
>20 carbon atoms/ solid at ambient conditions  ( nonadecane )

A carbon atom has 4 bonds—while a hydrogen atom has only one.

For saturated HC the proportion of carbon and hydrogen atoms in the molecule will be in accordance with the gen formula of Cn H2n+2


Thus methane CH4  ethane C2H6 and propane C3H8 are all saturated HC


Propylene C3H6 and butadiene C4H6 and ethylene C2H2 are unsaturated HC




CAPT AJIT VADAKAYIL ( 28 YEARS IN COMMAND )

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