Chemistry · General Awareness

Carbon and Fossil Fuels

1,756 Questions

Review fundamental concepts regarding carbon compounds, coal distillation, and fossil fuel formation. This segment covers the chemical properties and industrial applications of natural gas and crude oil. Practicing these questions will strengthen your chemistry foundation for general science sections.

Coal distillationPetroleum formationProperties of crude oilNatural gas applications

Carbon and Fossil Fuels Questions

Multiple choice chemistry the world of carbon organic compounds allotropes of carbon versatile nature of carbon

The number of free electrons in the outermost shell of carbon in graphite is:

  1. four

  2. one

  3. two

  4. three
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The number of free electrons in the outermost shell of carbon in graphite is one. Each $\displaystyle C$ atom is $\displaystyle sp^2$ hybridised. Each $\displaystyle C$ atom forms 3 covalent bonds with 3 other $\displaystyle C$ atoms. Thus, each $\displaystyle C$ atom has one electron in unhybridized $\displaystyle 2p$ orbital which it uses for $\displaystyle \pi $ bonding.

Multiple choice

What makes the motor of most cars run?

  1. water

  2. gasoline

  3. potatoes

  4. pure hope
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Most cars use an internal combustion engine that runs on gasoline. While electric cars exist, gasoline is the standard answer for most cars historically.

Multiple choice evs - i life is precious road safety and pollution pollution of natural resources air pollution and its effects

Aerosols having carbon and fluorine compounds are chiefly released by _______.

  1. Refineries

  2. Automobiles

  3. Industries

  4. Jets
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The propellants used for jet engine release the halogenated paraffin compounds called fluorocarbons and chlorofluorocarbons. Both of these compounds are the potent ozone-depleting substances. Refineries, automobiles and industries release the oxides of carbon, sulphur and nitrogen.

Hence, the correct answer is 'Jets'.

Multiple choice evs - i life is precious road safety and pollution pollution of natural resources air pollution and its effects

Knocking in a fuel is

  1. Tendency to spill

  2. Explosion of unburnt fuel-air mixture

  3. Late burning of fuel

  4. Difficult ignition of fuel in combustion chamber
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Knocking refers to the sensitivity shown by the fuel such as petrol. Due to this, petrol has low pressure and temperature of ignition and tends to ignite before the actual ignition spark in the air. This has deleterious effects on the engine and poses a great risk. To prevent this, the antiknocking agents like methyl tertiary butyl ether, toluene etc. are added to the fuel. These agents increase the temperature and pressure required for ignition.

Hence, the correct answer is 'Explosion of unburnt fuel-air mixture'.

Multiple choice chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

Which of the following is not a product of tar distillation?

  1. Phenol & naphthalene

  2. Benzol & pitch

  3. Anthracene & creosote

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The distillation of tar do not give Phenol & naphthalene, or Benzol & pitch or Anthracene & creosote.

Multiple choice chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

In the destructive distillation of coal, at 443-503 K temperature, a middle oil or carbolic oil fraction is obtained. This fraction contains :

  1. Phenol

  2. Xylenes

  3. Naphthalene

  4. Benzene
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

 (3) Distillation of coal tar : Arenes are isolated by fractional distillation of coal tar,

Table : 

Name of the fraction

Temperature range (K)

Main constituents

Light oil (or crude oil) fraction
Middle oil fraction (Carbolic oil)
Heavy oil fraction (Creosote oil)
Green oil (Anthracene oil)
Pitch (left as residue)

 So at 443-503 K temperature phenol and naphthalene is formed

Hence options A & C are correct.

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

The following is (are) endothermic reaction(s) :

  1. Combustion of methane.

  2. Decomposition of water

  3. Dehydrogenation of ethane to ethylene.

  4. Conversion of graphite to diamond.
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation

Combustion reaction are exothermic, hydrogenation of alkenes are exothermic and graphite is thermodynamically more stable.

Multiple choice zoology not for breathing not for drinking air pollution and its control air pollution - effects and control environmental issues

The automobile emission can be reduced by adding which of the following in the petrol?

  1. Barium salts

  2. Cadmium salts

  3. Cobalt salts

  4. Silicon 011
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The combustion of the fuel in the automobiles result in the production of emissions which contains toxic gases. The use of barium salts help in the reduction in the emissions from the burning of the fuels like petrol and diesel. However, the emissions which are released along with the barium salts have toxic effects on ingestion. The use of alkali metal salts like sodium, calcium, magnesium, potassium, etc which do not cause any effect are been used nowadays. 

Thus, the correct answer is option A. 

Multiple choice zoology not for breathing not for drinking air pollution and its control air pollution - effects and control environmental issues

In vehicles, catalytic converter are used to

  1. Increase mileage
  2. Convert $CO _2$ to carbonates

  3. Increase efficiency of lead petrol
  4. Convert CO to $CO _2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Catalytic convertors consist of expensive metals like platinum- palladium and rhodium as catalysts which are fitted in the automobiles to reduce the emission of poisonous gases. When the exhaust passes through catalytic convertor, unburnt hydrocarbons get converted into carbon dioxide and water, carbon monoxide is converted to carbon dioxide and nitric oxide is converted to nitrogen gas.
So, the correct answer is 'Convert CO to CO2'.
Multiple choice zoology not for breathing not for drinking air pollution and its control air pollution - effects and control environmental issues

The antiknock agent added to unleaded petrol is

  1. Tetraethyl lead

  2. Tetramethyl lead

  3. Dibromoethane

  4. Methyl Tertiary Butyl Ether (MTBE)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

MTBE is a gasoline additive, used as an oxygenate to raise the octane number. It is one of a group of chemicals commonly known as oxygenates because they raise the oxygen content of gasoline. It has been used in gasoline at low levels to replace tetraethyl lead and to increase its octane rating to help prevent engine knocking. Oxygenates help gasoline burn more completely, which causes emission of CO$ _2$ instead of CO.

Multiple choice zoology not for breathing not for drinking air pollution and its control air pollution - effects and control environmental issues

Antinocking agent added to petrol is commonly

  1. Tetramethyl or tetraethyl lead

  2. Dibromoethane

  3. Both A and B

  4. Octane
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Antiknocking agents are the chemical derivatives that are added to petrol. These agents increase the octane number of petrol due to which the pressure and temperature of petrol increases and so these protect petrol from detonation at low pressure. This is done to maintain the quality of the engines. Tetramethyl or tetraethyl lead, dibromoethane, benzole toluene are used as the antiknocking agents.

Hence, the correct answer is 'Both A and B'.

Multiple choice zoology not for breathing not for drinking air pollution and its control air pollution - effects and control environmental issues

Antiknocking agent of unleaded petrol is

  1. Dibromomethane

  2. Methyl-ethyl ether

  3. Propane

  4. Methyl tert. butyl ether
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Unleaded petrol is not doped with lead so it has a high knocking ability. It means it can be ignited before the actual ignition spark occurs. This is harmful to the engines. Lead is not used because it has shown severe adverse effects on the environment. Instead, methyl tertiary butyl ether is added which is easily miscible with petrol. However, it also has shown the carcinogenic properties.

Hence, the correct answer is 'Methyl tertiary butyl ether'.

Multiple choice zoology not for breathing not for drinking air pollution and its control air pollution - effects and control environmental issues

Catalytic convertor brings about

  1. Complete oxidation of hydrocarbons

  2. Oxidation of carbon monoxide to carbon dioxide

  3. Reduction of nitrogen oxide to nitrogen

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The catalytic converter is used to convert toxic and harmful pollutant into less toxic emission before they are released in the atmosphere from the engine of motor vehicles. The catalytic converter works as two types- reduction catalyst and the oxidation catalyst. The catalyst is a substance that causes or accelerates a chemical reaction without being unaffected. 
The catalytic converter reduces carbon monoxide hydrocarbon and nitrous oxides.
(A) The oxidation catalyst reduces the carbon monoxide by oxidizing by reacting carbon monoxide with oxygen in exhaust gas forming carbon dioxide.
(B) The oxidation catalyst burns the hydrocarbons and aids the reaction with leftover oxygen in the exhaust.
(C) The reduction catalyst separates nitrogen atom out of nitrous oxides and freezes oxygen, the nitrogen atom combines with another nitrogen atoms forming nitrogen.
Hence, the correct answer is 'All of the above'