Tag: hydrocarbons

Questions Related to hydrocarbons

The equation for the preparation of $CH _4$ from anhydrous sodium ethanoate [sodium acetate] is:
$CH _3COONa + NaOH \xrightarrow {CaO/\Delta } CH _4+ Na _2CO _3$

  1. True

  2. False


Correct Option: A
Explanation:

Reaction:
$CH _3COONa + NaOH \xrightarrow {CaO/\Delta } CH _4+ Na _2CO _3$
                                                        methane

Methane reacts with chlorine in the presence of sunlight. If this reaction is allowed to continue, the end product formed will be :

  1. carbon tetrachloride

  2. chloroform

  3. ethylene chloride

  4. chalcogons


Correct Option: A
In a highly refined form, liquid methane is used as a rocket fuel.
  1. True

  2. False


Correct Option: A
Explanation:

The given statement is True.
In a highly refined form, liquid methane is used as a rocket fuel.
Also, liquid methane is recently used for variety of bipropellant rocket engines.

Bakelite is a:

  1. Urea formaldehyde resin

  2. Phenol formaldehyde resin

  3. Both A and B

  4. None


Correct Option: B
Explanation:

Bakelite, a trademark of phenol-formaldehyde resin, trademarked synthetic resin invented in 1907 by Belgian-born American chemist Leo Hendrik Baekeland. 

A hard, infusible, and chemically resistant plastic, Bakelite was based on a chemical combination of phenol and formaldehyde (phenol-formaldehyde resin).

At room temperature and standard pressure, methane is a colorless, odourless gas.
  1. True

  2. False


Correct Option: A
Explanation:

The given statement is True.
At room temperature and standard pressure, methane is a colorless, odorless gas.
First four members are colourless, odourless gases, pentane to heptadecane are colourless, odourless liquids, while higher alkanes are colourless solids.

Marsh gas primarily contains :

  1. $CH _4$

  2. $C _2H _6$

  3. $H _2S$

  4. $C _2H _2$


Correct Option: A
Explanation:

Marsh gas is also called as methane. It is produced by the anaerobic bacterial decomposition of vegetable matter and the rumen of herbivorous animals.

When four moles of $O _2$ is used for complete combustion of methane.$1600kJ$ of heat is evolved.The calorific value of methane is ?

  1. $100 kJ/g$

  2. $800 kJ/g$

  3. $50kJ/g$

  4. $1600 kJ/g$


Correct Option: C
Explanation:

$CH _4+2O _2 \longrightarrow CO _2+2H _2O$             $\Delta H _f$

$\Rightarrow$ for $1$ mole methane   $2$ mole of oxygen is used.
$\Rightarrow$ for $2$ mole methane    $4$ mole of oxygen is used.
$\Rightarrow$ For $2$ mole $\Delta H= 1600$
$\Rightarrow$ For $1$ mole $\Rightarrow \cfrac {\Delta H}{2}=800KJ$
For $1g$ of $CH _4 \Rightarrow \cfrac {800}{16}=50KJ$

Methane is a major component of :

  1. biogas

  2. producer gas

  3. natural gas

  4. All of these


Correct Option: C
Explanation:

The main component of natural gas is methane. 

Generally, less than 5 percent of natural gas is ethane and propane. 
The main uses of methane natural gas are to generate electricity and make energy. Methane is the main component of natural gas. The combustion of methane releases energy, which is in the form of natural gas.

Chlorination of methane does not occur in dark because:

  1. methane can form free radicals in presence of sunlight only

  2. to get chlorine free radicals from $Cl _2$ molecules energy is required. It cannot happen in dark.

  3. substitution reaction can take place only in sunlight and not in dark

  4. termination step cannot take place in dark. It requires sunlight.


Correct Option: B
Explanation:
Chlorination of methane is a free radical substitution. To get chlorine free radical, UV light is required to initiate the substitution reaction, which is provided by sunlight.
$Cl _2\xrightarrow [  ]{ hv } Cl^{\bullet}+Cl^{\bullet}$

A controlled high temperature partial oxidation of methane gives:

  1. acetylene

  2. methanal

  3. methyl alcohol

  4. ethene


Correct Option: C