Tag: hydrocarbons

Quizzes (8) Questions (34)

Questions Related to hydrocarbons

Multiple choice methane study of methane carbon- an important element hydrocarbons chemistry

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

  1. oxygen

  2. chlorine

  3. butane

  4. methane
Reveal answer Fill a bubble to check yourself
D Correct answer
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
Multiple choice methane study of methane carbon- an important element hydrocarbons chemistry

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

  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.
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

Multiple choice methane study of methane carbon- an important element hydrocarbons chemistry

The correct composition of water gas is :

  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 $CO$
Reveal answer Fill a bubble to check yourself
A Correct answer
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. 

Multiple choice methane study of methane carbon- an important element hydrocarbons chemistry

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

  1. Halogenation

  2. Free radical halogenation

  3. Methylation

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

Multiple choice chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

Sodium fumarate on Kolbes electrolysis gives :

  1. Ethene

  2. Ethyne

  3. Ethane

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

Kolbe's electrolysis of sodium fumarate (a salt of an unsaturated dicarboxylic acid) results in the formation of ethyne (acetylene) due to the elimination of CO2 and formation of a triple bond.

Multiple choice chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

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

  1. methane

  2. ethane

  3. ethylene

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

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

Multiple choice chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

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

  1. $1$ hexyne
  2. $2- hexyne$
  3. $3$ hexyne
  4. $3$ methyl $1$ pentyne
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

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

  1. Ethene

  2. Ethane

  3. Butane

  4. Ethyne

  5. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Electrolysis of the potassium salts of fumaric or maleic acid (unsaturated dicarboxylic acids) yields ethyne via Kolbe's electrolysis.

Multiple choice chemistry hydrocarbons introduction to alkenes - ethyne acetylene alkynes

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

  1. ethene can not burn in air

  2. incomplete combustion takes place

  3. ethene burn in air with explosion

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
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.