Tag: hydrocarbons

Questions Related to hydrocarbons

When vegetable matter decays at the bottom of lakes and ponds where there is limited air, it gives rise to 'marsh gas', which is:

methane study of methane carbon- an important element hydrocarbons chemistry

  1. oxygen

  2. chlorine

  3. butane

  4. methane

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Correct Option: D
Explanation:
(i) Marsh gas is a mixture of methane, hydrogen sulfide and carbon dioxide which has methane at high percentage compared to the other two compounds.
(ii) Marsh gas is produced naturally in flooded regions.
(iii) This condition allows anaerobic digestion and fermentation of organic matter which produces methane

Statement I: Methane is defined as a compound
Statement II: Methane can be broken down chemically

methane study of methane carbon- an important element hydrocarbons chemistry

  1. Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1

  2. Both the Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1

  3. Statement 1 is correct but Statement 2 is not correct.

  4. Statement 1 is not correct but Statement 2 is correct.

  5. Both the Statement 1 and Statement 2 are not correct.

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Correct Option: A
Explanation:

Statement I: methane is defined as a compound
statement II: Methane can be broken down chemically
Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.
Note: Compounds are defined as substances of definite compositions which can be decomposed into two or more substances by a simple chemical process.

The correct composition of water gas is :

methane study of methane carbon- an important element hydrocarbons chemistry

  1. mixture of $H _2$ and $CO$

  2. mixture of $N _2$ and $CO$

  3. mixture of $He$ and $CO$

  4. mixture of $O _2$ and $CO$

Show answer
Correct Option: A
Explanation:

Water gas is produced from synthesis gas, which is composed of carbon monoxide and hydrogen. Syngas is a useful product, but requires careful handling due to its flammability and the risk of carbon monoxide poisoning. 

Reaction of methane with halogens under appropriate conditions is called as :

methane study of methane carbon- an important element hydrocarbons chemistry

  1. Halogenation

  2. Free radical halogenation

  3. Methylation

  4. Chlorination

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Correct Option: B
Explanation:

Methane reacts with halogens given appropriate conditions as follows:

${X} _{2} + UV \rightarrow  2 X \cdot$

$X \cdot + C{H} _{4} \rightarrow HX + C{H} _{3} \cdot$

$C{H} _{3} \cdot + {X} _{2} \rightarrow C{H} _{3}X + X \cdot$

where $X$ is a halogen: fluorine $\left(F\right)$, chlorine $\left(Cl\right)$, bromine $\left(Br\right)$, or iodine $\left(I\right)$. This mechanism for this process is called free radical halogenation.

Which are the gases formed in a biogas plant?

methane study of methane carbon- an important element hydrocarbons chemistry

  1. $CO, CH _{4}$

  2. $CH _{4}, CO _{2}$

  3. $CO _{2}, O _{2}$

  4. $N _{2}, S _{2}$

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Correct Option: A

Sodium fumarate on Kolbes electrolysis gives :

chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

  1. Ethene

  2. Ethyne

  3. Ethane

  4. Methane

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Correct Option: B

The compound used in Hawker's lamp and in light houses for illumination purposes is :

chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

  1. methane

  2. ethane

  3. ethylene

  4. acetylene

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Correct Option: D
Explanation:

Acetylene is used in-
Illumination of cycle lamps, hawker's lamps and buoys in light houses.
Producing oxyacetylene flame for welding and cutting.

A hydrocarbon of molecular formula , ${C _6}{H _{10}}$ reacts with sodamide and the same on ozonolysis followed by hydrogen peroxide gives two molecules of carboxylic acids, one being optically active. Then the hydrocarbon may be

chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

  1. $1$ hexyne

  2. $2- hexyne$

  3. $3$ hexyne

  4. $3$ methyl $1$ pentyne

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Correct Option: A

Product formed on electrolysis of potassium salt of fumaric and maleic acid is

chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

  1. Ethene

  2. Ethane

  3. Butane

  4. Ethyne

  5. None of the above

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Correct Option: D

A mixture of oxygen and ethyne is burnt for welding. Why a mixture of ethyne and air is not used?

chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

  1. ethene can not burn in air

  2. incomplete combustion takes place

  3. ethene burn in air with explosion 

  4. none of these

Show answer
Correct Option: B
Explanation:

When ethyne is burnt in air incomplete burning takes place and produce sooty flame due to limited supply oxygen present in the air.


 However, if ethyne is burnt in oxygen, it gives a clean flame with high temperature (3000°C ) due to complete combustion of ethyne.

 Hence, This oxy-acetylene flame is used for welding and it is not possible to attain such a high temperature with air. Due this reason a mixture of ethyne and air is not used for welding.