Tag: rocks and minerals

Questions Related to rocks and minerals

Compounds with more than 100 and less than 0 octane numbers are not known.

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. True

  2. False

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Correct Option: B
Explanation:

Compounds with more than 100 and less than 0 octane numbers are  also known. For example triptane has octane number of 125 and n -nonane has octane number of -45.

Branching of chain decreases the value of octane number.

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. True

  2. False

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Correct Option: B
Explanation:

Branching of chain increases the value of octane number.

Which of the following will increase the octane number of gasolines?

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. cracking

  2. alkylation

  3. isomerisation

  4. all of the above

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Correct Option: D
Explanation:

Cracking, alkylation and isomerization will increase the octane number of gasolines.


 

The addition of which of the following will increase the octane number of gasoline?

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. benzene

  2. toluene

  3. xylene

  4. all of the above

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Correct Option: D
Explanation:

The addition of benzene, toluene and xylene will increase the octane number of gasoline.

During carbonisation or destructive distillation of coal, bituminous coal is heated in iron or fire clay retorts to high temperature (500 deg C) in presence of air.

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. True

  2. False

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Correct Option: B
Explanation:

During carbonization or destructive distillation of coal, bituminous coal is heated in iron or fireclay retorts to high temperature (1000-1400 deg C) in absence of air.

In cracking, reaction is propagated through:

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. absorption of hydrogen by the formed radical

  2. release of hydrogen by the formed radical

  3. gain of electrons by the formed radical

  4. release of electron by formed radical

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Correct Option: A
Explanation:

In propagation step of cracking process, a free radical removes a hydrogen atom from another molecule, turning the second molecule into a free radical.

Which one is true for the octane number of following organic compounds?

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. Aromatic Compound $>$ Aliphatic compound

  2. Aromatic compound $<$ Aliphatic compound

  3. Aromatic compound $=$ Aliphatic compound

  4. None of the above

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Correct Option: A
Explanation:
The octane number of a fuel is based on how fuels auto-ignite, under compression.
1. It is based on the scale where isooctane is 100 (minimal ignition under pressure) and heptane is 0 (easily ignites under pressure).
For example, petrol with an octane number of 92 has the same knock as a    mixture of 92% isooctane and 8% heptane.
2. Octane rating decreases with an increase in the carbon chain length.
3. Octane ratings increase with carbon chain branching.
4. Octane ratings increase in aromatics with the same number of carbons.

Hence, the correct option is $A$

In steam cracking, initiation usually involves breaking a chemical bond between:

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. carbon and hydrogen atom

  2. carbon atoms

  3. carbon-hydrogen and carbon-carbon simultaneously

  4. no bond is completely broken in initiation

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Correct Option: B
Explanation:

In steam cracking, initiation usually involves breaking a chemical bond between two carbon atoms, rather than the bond between a carbon and a hydrogen atom.

Most of the chemical reactions in Cracking is based on:

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. Carbocation formation

  2. Carbanion formation

  3. Radical formation

  4. Zwitter ion formation

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Correct Option: C
Explanation:

In cracking, the initial process involves the breaking down of hydrocarbons into free radicals.Only a small fraction of the feed molecules actually undergo initiation, but these reactions are necessary to produce the free radicals that drive the rest of the reactions.

Select the correct option about the Octane number of the organic compound.

chemistry energy rocks and minerals petroleum and natural gas fossil fuels

  1. Saturated compound $>$ Unsaturated compound

  2. Saturated compound $<$ Unsaturated compound

  3. Saturated compound $=$ Unsaturated compound

  4. Both A and B

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Correct Option: B
Explanation:

An unsaturated compound has a higher octane rating than a saturated compound.