Main constituents of coal gas are; $CH _{4}, H _{2}$ and CO.

Coke obtained by destructive distillation of coal is not used for drinking purposes. But it is largely used as a reducing agent in the extraction of metals from their ores.

Among all, Kerosene have highest calorific value, hence it is used as aviation fuel in jet aeroplane.

Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, but commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.

Natural gas mainly contains methane which on heating with water produces carbon monoxide and hydrogen. 

Petroleum is formed from dead organic matter. When a large amount of dead organism, usually zooplankton and algae are buried underneath sedimentary rock and subjected to intense heat and pressure after such a process the molecule turn into petroleum.Zooplankton is organism found in ocean and seas. This organism can't be found on land, on the rock, on the plant. So option "C "is the right answer.

The petroleum product used as fuel for stoves, lamps and jet aircraft is kerosene.

On burning natural gas it does not produce harmful gases, hence it is less polluting fuel.

Petrol, is the odd one out. Since, the coal, charcoal, firewood are solid natural resources that are obtained from nature, while petrol is liquid fuel.

Petroleum resource is a non renewable resource.
The limited quantity of petroleum is present in the earth which when exhausted cannot be obtained again.

Thermal power plants make use of coal, petroleum and natural gas.

Petroleum is also called as the black gold because it is the important source of energy. Byproducts of petroleum are very valuable and expensive.

Natural gas is formed by the action of anaerobic bacteria on the plants or vegetation thousand of years ago.Over the years under high temperature and pressure, methane gets converted to natural gas.

Petroleum is a fossil fuel which is formed deep under the earth's crust in thousands of years which is a non renewable resource which once depleted cannot be replenished back.It cannot be made artificially in the laboratories.

1) Bitumen is the one of the component of petroleum which is used for metalling / surfacing the roads.

Coal is a fossil fuel derived from organic matter. We get coal deep inside the Earth's crust in coal mines. When dead plants got buried into the bottom of the soil. Due to high pressure and temperature plants gets converted into fossil fuels. If it is burn in large quantity it causes pollution.

CNG is made by compressing natural gas (which is mainly composed of methane, CH₄ stored at high pressure), to less than 1 percent of the volume, it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of 20–25 MPa (2,900–3,600 psi), usually in cylindrical or spherical shapes.

Methane is the important constituent (95%) of natural gas. Methane has high heat of combustion. Hence, it is used as fuel.
$CH _4 + 2O _2 \rightarrow CO _2 + 2H _2O + heat$

Fractional distillation is used for refining of petroleum.

The number of carbon atoms in petrol is $C _{7}-C _{9}$.

Natural gas is primarily composed of methane, but also contains ethane, propane and heavier hydrocarbons. It also contains small amounts of nitrogen, carbon dioxide, hydrogen sulphide and trace amounts of water.

LPG is liquefied petroleum gas. The main components are:

In its strictest sense, petroleum includes only crude oil, but in common usage, it includes all liquid, gaseous and solid hydrocarbons.Under surface pressure and temperature conditions, lighter hydrocarbons methane, ethane, propane and butane occur as gases, while pentane and heavier hydrocarbons are in the form of liquids or solids.

Because heavier crude oils have too much carbon and not enough hydrogen, the cracking processes generally involve removing carbon from or adding hydrogen to the molecules and using fluid catalytic cracking to convert the longer, more complex molecules in the oil to the shorter, simpler ones in the fuels.

In the reservoir, crude oil is usually found in association with natural gas, which is lighter forms a "gas cap" over the petroleum, and saline water which, being heavier than most forms of crude oil, generally sinks beneath it.

Petroleum is a mixture of a very large number of different hydrocarbons; the most commonly found molecules are alkanes(kinds of paraffin), cycloalkanes(naphthenes), aromatic hydrocarbons, or more complicated chemicals like asphaltenes. Each petroleum variety has a unique mix of molecules, which define its physical and chemical properties, like colour and viscosity.

In its strictest sense, petroleum includes only crude oil, but in common usage it includes all liquid, gaseous and solid hydrocarbons.Under surface pressure and temperature conditions, lighter hydrocarbons methane,ethane,propane and butane occur as gases, while pentane and heavier hydrocarbons are in the form of liquids or solids.

In its strictest sense, petroleum includes only crude oil, but in common usage, it includes all liquid, gaseous and solid hydrocarbons.Under surface pressure and temperature conditions, lighter hydrocarbons methane, ethane, propane and butane occur as gases, while pentane and heavier hydrocarbons are in the form of liquids or solids.

 $2,2,4-$trimethylpentane (isooctane), widely used in gasoline, has a chemical formula of $C _8H _8$ and it reacts with oxygen exothermically as shown below:

$2C _8H _{18}(l) + 25O _2(g) \longrightarrow 16CO _2(g) + 18H _2O(g)$

Crude oil is the raw material which is obtained from the earth's crust by drilling. It is brownish black in colour. It is then refined to obtain useful products such as petrol, diesel, kerosene, lubricating oil, etc. 

It tells us about the quality of gasoline whether there is some contamination present or the gasoline obtained is of low quality. The colour also shows us the indication whether it has gone through some chemical change. It shows gum forming tendency and thoroughness of the refining process.

Aviation turbine fuel means a refined middle distillate suitable for fuel in an aviation gas turbine internal combustion engine. Its boiling point is closest to that of kerosene.

The crude oil which is obtained from the earth's crust is in the raw form. It is refined in a refining tower. In this tower, the crude oil is heated at a temperature of 400 C. 

The process of formation of petroleum causes the organic matter to change, first into a waxy material known as kerogen, which is found in various oil shales around the world, and then with more heat into liquid and gaseous hydrocarbons via a process known as catagenesis.

Gasoline is a volatile mixture of liquid hydrocarbons generally containing small amounts of additives suitable for use as a fuel in a spark ignition internal combustion engine. The presence of sulphur in gasoline is undesirable due to its foul odour and also it forms gums.

Kerosene has been used for illumination since centuries. The capacity of kerosene to be illuminating depends on the luminosity number of kerosene. 

Glycol added to petrol acts as anti -icing agent

Diesel fuel is a mixture of hydrocarbons with boiling points in the range of 150 to 380°C which are obtained from petroleum.

Aromatics are desirable in diesel and kerosene but is undesirable in gasoline. It is a mixture of paraffin (alkanes), cycloalkanes (naphthenes), and olefins (alkenes). Aromatics are a base component of gasoline derived from crude oil. Refiners manipulate these substances – mainly mixtures of chemicals like benzene, toluene, and xylene – to increase the octane rating, a measure of how well the fuel actually works.

Petroleum is a non-renewable natural resource. It gets exhausted because it is not a natural renewable source.

Petroluem is known as black gold as it is black coloured crude oil that is extracted from earth's crust and it has its value as it is limited in stock, takes millions of years to form and is costly available.

Crude petroleum is the multi component mixture consisting of many compounds. It is drilled from the earth's crust and then refined in the petroleum refineries. Its molecular weight is around $1500$.

The density of gasoline ranges from 0.71–0.77 kg/L, where as that of water is 1kg/L, oil is less dense than water so it will "float" on water. Gas is less dense than both and will float to the top. higher densities having a greater volume of aromatics. Since gasoline floats on water, water cannot generally be used to extinguish a gasoline fire unless used in a fine mist. The petroleum products will separate by density.

Petroleum Conservation Research Association is a registered society set up under the aegis of Ministry of Petroleum & Natural Gas, Government of India (MoP&NG). PCRA is a national government agency engaged in promoting conservation of petroleum products & energy efficiency in various sectors of economy.

Sewer gas is a complex mixture of toxic and nontoxic gases produced  by the decomposition of organic household or industrial wastes.

Sewer gas is a complex mixture of toxic and nontoxic gases produced and collected in sewage systems by the decomposition of organic household or industrial wastes, typical components of sewage. Sewer gases may include hydrogen sulfide, ammonia, methane, esters, carbon monoxide, sulfur dioxide and nitrogen oxides.

The Petroleum Conservation Research Association (PCRA) is an organization established in India in 1978. It helps the government in proposing policies and strategies aimed at reducing India's dependency on oil, in order both to save money and to reduce the environmental impact of oil use.

Petroleum (also known as crude oil or simply oil) is a fossil fuel that was formed from the remains of ancient marine organisms. Millions of years ago, algae and plants lived in shallow seas. After dying and sinking to the seafloor, the organic material mixed with other sediments and was buried.

The statements (A), (C) and (D) are true. Natural gas is an important fossil fuel as it is easy to transport through pipes. Natural gas is stored under high pressure as compressed natural gas (CNG). CNG is used for power generation. CNG is used as fuel for transport vehicles as it is less polluting. It is a cleaner fuel.

It is difficult to transport natural gas through pipelines as it poses safety concerns due to the flammable nature of natural gas.

Impervious rocks are rocks which squeeze both oil and gas between them. Petroleum is obtained deep down from these impervious rocks.

Petroleum oil is found deep underground in seabeds. 

Petroleum is formed from natural process from plants and animal residues and is an example of fossil fuel.  

The dead aquatic organisms that were buried under the sand and clay of the seabed, were converted to petroleum owing to the absence of air, high temperature, and high pressure.

A diesel generator is the combination of a diesel engine with an electric generator(often an alternator) to generate electrical energy. 

Petroleum which is also known as crude oil  is a fossil fuel that was formed from the remains of  marine organisms and plant wastes (vegetable).

Millions of years ago, algae and plants lived in shallow areas  seas. After dying and sinking to the seabottom, the organic material mixed with other sediments and was buried. Over millions of years under high pressure and high temperature, the remains of these organisms transformed into what we know today as fossil fuels by the various chemical process . Coal, natural gas, and petroleum are all fossil fuels that formed under similar conditions.

Hence option D is corrrect.

The correct sequence is :
(i) Drilling of the oil through the various layers under the earth's surface.
(ii) Processing of crude oil to remove heavy oil.
(iii) Purification of crude oil containing salt water.
(iv) Heating of the crude oil containing pure mixture of hydrocarbons over a specific range of temperature.
(v) Separation of constituents by fractional distillation.

Petroleum is lighter than water. It has less density, so is insoluble in water.

It is 'ethyl mercapton' which is responsible for the pungent smell.

A fractionating column is an essential thing which is used in distillation of liquid mixtures so as to separate the mixture into its component parts, or fractions, based on the differences in their boiling temparatures. Fractionating columns are used in small scale laboratory distillation process as well as for large scale industrial distillations.

Hence option B is correct.

Procedure for extraction of petroleum:

Petroleum is imported into India from other Arab countries with a cost of Rs. $3100$ crores.

Vacuum distillation is a distillation of a liquid under reduced pressure, enabling it to boil at a lower temperature than normal.

Steam distillation of a liquid in a current of steam used especially to purify liquids that are not very volatile and are immiscible with water.

Fractional distillation is a separation of a liquid mixture into fractions differing in boiling point (and hence chemical composition) by means of distillation, typically using a fractionating column.

The various fractions of petroleum are separated by fractional distillation.
Fractional distillation is one separation of a mixture into its components parts, or fractions, sour as in separating chemical compounds by their boiling point by heating them to a temp at which one or more fractions of the compound will vaporize.

Since crystallization generally produces salts which are crystalline in state or $100$ percent purity in state.

Two compounds which have different solubilities in a solvent S can be separated from each other by Fractional Crystallisation. The process involves a series of repeated-crystallisations. The mixture of the two compounds in the solvent S is heated so as to make it saturated. When the hot solution is allowed to cool, the less soluble substance crsytallises out first while the more soluble substance remains in the solution. The crystals of first compound are separated from the mother liquor and the mother liquor is again concentrated and allowed to cool when the crystals of the 2nd compound are obtained.

Separation of a mixture into its components whose boiling points are different is called Fractional distillation.
This method is used for separating a mixture of two or more volatile liquids both having close boiling points. The boiling points of two components differ by 10-15 K. For example, acetone and methanol with boiling points 329 K and 338 K can be separated  by this method. This method is used for distillation of petroleum, coal tar and crude alcohol.

During fractional distillation, light oil or crude naphtha is collected upto 170$^o$.

90% benzol is named so because 100. c.c of the fraction when distilled below 100 deg C gives 90 c.c of distillate.
90% benzol contains 70% benzene, 24% toluene and 3-5% xylene.

Anthracene, phenanthrene, etc. represent the chief constituents of green oil.

Cresols, naphthalene, etc. represents the chief constituents of Creosote oil.

Ammonia liquor is prepared by dissolving Ammonia in water. Ammonia liquor is also known as ammonia water or some times known as ammonium hydroxide.
In aqueous solution, ammonia deprotonates a small fraction of the water to give ammonium and hydroxide according to the following equilibrium:
$ NH _3 +H _2O\rightarrow NH _4^{+} + OH^{-}$

During fractional distillation,  carbolic oil or middle oil is collected up to 170 - 230 $^o$.

During fractional distillation of coal-tar, the pitch is obtained as a residue.

50% benzol or 90% Toluol is named so because 50% of it distills upto 100 deg C and 90% of it distills between 110-140 deg C. 50% benzol or 90% Toluol consists mainly of xylenes and small amounts of benzene and toluene.

Benzene, toluene and xylene, obtained during fractional distillation of 50% benzol or 90% Toluol are used as solvents. They are also used in dry cleaning, as fuel and for preparing dyes, drugs, explosives etc.

All of the following statements are true.
When carbolic oil is cooled, naphthalene crystallizes out.
Naphthalene is purified by sublimation.
Naphthalene is used for manufacture of dyes, drugs, explosives etc.

The percent of xylene present in 90% benzol is 3-5%.

solvent naphtha or benzin is used as a solvent for paints, resins, rubber etc.

Light oil or crude naphtha contains pyridine.
Whereas middle oil or carbolic oil contains phenol and naphthalene and green oil contains anthracene.

Anthracene oil shows green fluorescence. Hence, it is also named green oil.

All of the given statements are true regarding creosote oil.
It contains cresols along with some naphthalene and quinoline.
It is not worked up because its constituents are more easily obtained by synthetic methods.
It is used as such under the name of creosote oil for the preservation of wood and for the manufacture of some disinfectants.

Green oil contains anthracene that is used for the manufacture of alizarin dyes.

 Pitch or undistilled residue is used in varnishes, road-making and protecting wood and metal work

The percent of carbon present in pitch is 92-94%.

Coal tar is a complex mixture of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds but it is mainly used as the main source for aromatic compounds.

When fractional distillation of coal tar is carried out,  the maximum percentage is of pitch. Pitch is undistilled residue. It is about 50-60%.

During the fractional distillation of coal tar, the fraction which has minimum percentage is light oil or crude naphtha. It is obtained only $1.5-2\%$ in the distillation.

Separation of $2$ substances by crystallization depends upon their difference in solubility as more soluble impurity will go into the solution and less soluble component will crystallize out.

Coal, petroleum gas and petrol are fossil fuels. Fossil fuels are good for one time use. But wind is a renewable source of energy.