Test: Properties of Hydrocarbons - UPSC MCQ

Conversion of methane to Carbon tetrachloride is a substitution reaction as hydrogen atoms are replaced by chlorine atoms.

Product of the reaction represented by "X":
The likely product of the reaction represented by "X" is CH₃Cl + HCl.

Explanation:
1. The given reaction shows the addition of chlorine (Cl₂) to methane (CH₄) in the presence of sunlight.
2. The reaction will result in the substitution of one hydrogen atom in methane with one chlorine atom, forming a chlorine-substituted methyl group.
3. The chlorine atom will replace one hydrogen atom in methane, resulting in the formation of CH₃Cl (methyl chloride).
4. Since the reaction involves the addition of chlorine (Cl₂), it is likely that a byproduct of the reaction will be HCl (hydrochloric acid).
5. Therefore, the product of the reaction represented by "X" is CH₃Cl + HCl.

Unsaturated hydrocarbons like ethyne also known as acetylene burn to produce a yellow sooty flame due to incomplete combustion in air.

The flame is sooty because the percentage of carbon is comparatively higher than that of alkanes and so does not get completely oxidized in air.

CH₄(g)+2O₂(g)→CO₂(g)+2H₂O(g)+ Heat + Light

Homologous Series of Alkynes
Alkynes are a type of hydrocarbon compound that contains a carbon-carbon triple bond. They belong to a homologous series, which means that they have a similar chemical structure and follow a specific pattern in their molecular formula. Each member of the homologous series differs from the previous member by a repeating unit of -CH₂-.
The molecular formula for alkynes can be represented as C_nH_2n-2, where n represents the number of carbon atoms in the molecule.
Identifying the Alkyne
Out of the given options, only one compound belongs to the homologous series of alkynes based on the molecular formula:
B: C₃H₄
Let's analyze the molecular formula of each option to identify the alkyne:
A: C₆H₆ - This molecular formula represents benzene, an aromatic compound. It does not contain a carbon-carbon triple bond, so it is not an alkyne.
B: C₃H₄ - This molecular formula satisfies the general formula for alkynes (C_nH_2n-2). It represents a three-carbon alkyne with the molecular formula C₃H₄. Therefore, option B belongs to the homologous series of alkynes.
C: C₂H₆ - This molecular formula represents ethane, which is an alkane. Alkanes do not have carbon-carbon triple bonds, so they are not alkynes.
D: C₂H₄ - This molecular formula represents ethene, which is an alkene. Alkenes have a carbon-carbon double bond, but not a triple bond like alkynes.

Conclusion
Based on the given options, only option B (C₃H₄) belongs to the homologous series of alkynes. It satisfies the molecular formula for alkynes (CnH_2n-2) and represents a three-carbon alkyne.

Because it is a saturated hydrocarbon and saturated ones doesn't go addition. But it will undergo substitution reaction.

Alkaline potassium permanganate is a good oxidising agent.

Addition of hydrogen across C-C double bonds is called hydrogenation. Unsaturated hydrocarbons add hydrogen in the presence of catalysts such as nickel/palladium to give saturated hydrocarbons. Vegetable oils used for cooking are long unsaturated hydrocarbons which are healthy.

Incomplete combustion of fuel gives out sooty flame which contains unburnt carbon particles which deposits on the bottom of cooking utensils.

Oxidation is gain of oxygen. In this reaction oxygen is added to the reactant to form product. 

Saturated hydrocarbons contain C-C single bond and on complete combustion they produce large amounts of heat. The cooking gas used in house is Butane (C₄H₁₀) known as LPG or Methane (CH₄) known as CNG.

The chemical formula of benzene is C6H6, so it has six carbon atoms and six hydrogen atoms.

The reaction in which an element or molecule is added to unsaturated hydrocarbons is called addition reaction.

The reaction in which an element or molecule is added to unsaturated hydrocarbons is called addition reaction. In the above reaction unsaturated hydrocarbon is converted into saturated hydrocarbon.

Pentane (C₅H₁₂) is an organic compound with five carbon atoms. Pentane has three structural isomers that are n-pentane, Iso-pentane (methyl butane), and neopentane (dimethylpropane).