Organic Chemistry

Step 1: Understanding the Concept:
Addition reactions occur in unsaturated hydrocarbons (alkenes and alkynes) where the double or triple bonds break to accommodate new atoms.

Step 2: Detailed Explanation:
Hydrogenation: It is a chemical reaction where hydrogen gas ( ) is added to an unsaturated hydrocarbon in the presence of a catalyst like finely divided Nickel (Ni) or Palladium (Pd) to form a saturated hydrocarbon.
Industrial Application: This process is widely used commercially for the hydrogenation of vegetable oils.
Liquid vegetable oils (which contain unsaturated fatty acids) are reacted with hydrogen to produce solid or semi-solid vegetable ghee (which contains saturated fatty acids, e.g., Vanaspati ghee).

Step 3: Final Answer:
It converts unsaturated hydrocarbons to saturated ones and is used industrially to convert liquid vegetable oils into solid fats.

Step 1: Understanding the Concept:
Vinegar is a common household item used for cooking and preservation, chemically derived from an organic acid.

Step 2: Detailed Explanation:
Vinegar is essentially a dilute solution containing about 5% to 8% acetic acid ( , also known as ethanoic acid) in water.
It is produced through the fermentation of ethanol by acetic acid bacteria.

Step 3: Final Answer:
It is a 5-8% aqueous solution of acetic acid.

Step 1: Understanding the Concept:
Structural isomers are molecules with the same molecular formula but a different arrangement of atoms (different structure).

Step 2: Detailed Explanation:
The molecular formula represents butane, an alkane. It has two structural isomers:
1. n-butane (normal butane): A straight, unbranched chain of four carbon atoms.
Structure:
2. Isobutane (IUPAC name: 2-methylpropane): A branched chain where a methyl group is attached to the central carbon of a three-carbon chain.
Structure:

Step 3: Final Answer:
The two isomers are the straight-chain n-butane and the branched-chain isobutane.

Step 1: Understanding the Concept:
IUPAC naming requires counting the longest carbon chain and identifying functional groups or multiple bonds.

Step 2: Detailed Explanation:
The given structure is .
1. Count carbons: The longest continuous carbon chain has 3 carbon atoms. The root word for 3 carbons is "prop".
2. Identify bonds: There is a triple bond between carbon atoms. The suffix for a triple bond is "-yne".
3. Numbering: Number the chain from right to left to give the triple bond the lowest possible number (position 1). However, since there are only 3 carbons, the triple bond must be between C1 and C2 regardless of which end it is on. Thus, the position number (1) is often omitted.
Combining these gives Prop + yne.

Step 3: Final Answer:
The IUPAC name is Propyne.

Step 1: Understanding the Concept:
The name "ethanoic acid" gives us two clues: "eth-" means 2 carbon atoms, and "-oic acid" means it contains a carboxylic acid functional group ( ).

Step 2: Detailed Explanation:
Start with a two-carbon skeleton: .
Turn one of the carbons into a carboxyl group: .
Fill the remaining valencies of the first carbon with hydrogen atoms. Carbon needs 4 bonds, so it gets 3 hydrogens.
The resulting formula is .
The fully expanded structural formula shows all bonds:
One carbon is bonded to three hydrogens.
It is single-bonded to a second carbon.
The second carbon is double-bonded to an oxygen atom and single-bonded to a hydroxyl ( ) group.

Step 3: Final Answer:
The structural formula is .

Step 1: Understanding the Concept:
A functional group is an atom or group of atoms within a molecule that determines the chemical properties of that molecule.
Most common functional groups in organic chemistry contain carbon (e.g., aldehyde , carboxyl ).

Step 2: Detailed Explanation:
The question asks for a functional group that does not contain a carbon atom itself.
The Hydroxyl group ( ), present in alcohols, consists only of oxygen and hydrogen.
The Amino group ( ), present in amines, consists only of nitrogen and hydrogen.
Either is a correct answer.

Step 3: Final Answer:
The Hydroxyl group ( ) is a carbon-less functional group.

Step 1: Understanding the Concept:
A homologous series is a family of organic compounds that share the same general formula and similar chemical properties.

Step 2: Detailed Explanation:
Let's test the given formulas against general formulas for hydrocarbons:
Alkanes:
Alkenes:
Alkynes:
Option (A) : , . This is an alkane (Methane).
Option (B) : , . This is an alkane (Ethane).
Option (D) : , . This is an alkane (Butane).
Option (C) : , . This fits the alkyne formula ( ). It is Propyne.
Since options A, B, and D are alkanes, option C (an alkyne) is the odd one out and does not belong to the same homologous series.

Step 3: Final Answer:
is not an alkane.