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CONCEPT:

Reduction Reaction

• A reduction reaction involves the gain of electrons by a molecule, atom, or ion.
• It is the opposite of an oxidation reaction, which involves the loss of electrons.
• In a reduction reaction, the oxidation state of the species decreases.

EXPLANATION:

• In the given reactions:

I. 2Ag⁺(aq) + 2e^- → 2Ag(s)

II. Cu(s) → Cu²⁺(aq) + 2e^-

• Reaction I: 2Ag⁺(aq) + 2e^- → 2Ag(s)
• Silver ions (Ag⁺) are gaining electrons to form silver metal (Ag).
• This is a reduction reaction because there is a gain of electrons.
• Reaction II: Cu(s) → Cu²⁺(aq) + 2e^-
• Copper metal (Cu) is losing electrons to form copper ions (Cu²⁺).
• This is an oxidation reaction because there is a loss of electrons.
• Therefore:
• Only Reaction I is a reduction reaction.
• Reaction II is an oxidation reaction.

The correct answer is option 4: Only I.

CONCEPT:

IUPAC Naming of Alcohols

• The IUPAC naming system is a standardized method for naming chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC).
• For alcohols, the base name is derived from the longest carbon chain that includes the carbon atom bonded to the hydroxyl group (-OH).
• The position of the hydroxyl group is indicated by a number, and the suffix -ol is added to the base name of the hydrocarbon.
• If there are multiple hydroxyl groups, the suffixes -diol, -triol, etc., are used along with the appropriate numbers to indicate their positions.

EXPLANATION:

• Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic.
• The structure of glycerol includes a three-carbon chain with each carbon bonded to a hydroxyl group (-OH).
• According to IUPAC naming rules:
• The base name is propane, as the longest carbon chain has three carbon atoms.
• The three hydroxyl groups are located on the first, second, and third carbon atoms.
• Therefore, the IUPAC name of glycerol is Propane-1,2,3-triol.

Therefore, the IUPAC name of Glycerol is Propane-1,2,3-triol.

CONCEPT:

Drawback of Octet Theory

• The octet theory, proposed by Gilbert Lewis and Walther Kossel, primarily focuses on the tendency of atoms to prefer having eight electrons in their valence shell.
• Although it has been widely accepted and used to explain the formation of chemical bonds, it has certain limitations.

EXPLANATION:

• Statement I: This theory does not account for the shape of molecules.
• The octet theory focuses on the stability provided by having eight electrons in the valence shell but does not provide any insight into the three-dimensional arrangement of atoms in a molecule.
• It does not explain the geometric shapes of molecules, such as the linear, trigonal planar, tetrahedral, or other complex shapes observed in molecules.
• Statement II: It does not explain the relative stability.
• The octet theory also falls short in explaining why some molecules are more stable than others even if they have complete octets.
• Stability is influenced by factors such as bond energy, resonance, hybridization, and molecular interactions, which are not considered by the octet theory.
• Both statements highlight significant limitations of the octet theory, making both statements correct.

Therefore, the correct answer is Both I and II.

CONCEPT:

Boyle's Law

• Boyle's Law states that the pressure (p) of a given mass of gas is inversely proportional to its volume (V) at a constant temperature.
• The mathematical expression of Boyle's Law is:

p ∝ 1/V or pV = k (where k is a constant)

EXPLANATION:

• In Boyle's Law, when plotting the graph of pressure (p) against the reciprocal of volume (1/V), it shows a direct relationship.
• This means that as the volume decreases (and thus 1/V increases), the pressure increases proportionally.
• Hence, the graph of (p) versus (1/V) is a straight line passing through the origin.

Therefore, the graph between (p) and (1/V) in Boyle's law is a straight line.

CONCEPT:

Butanedioic Acid

• Butanedioic acid is a dicarboxylic acid with the formula HOOC-CH2-CH2-COOH.
• It is a naturally occurring substance found in various organisms and is involved in the citric acid cycle.
• In its common form, butanedioic acid is known by a different name.

EXPLANATION:

• The common name of butanedioic acid is derived from its structure and origin.

Butanedioic acid has two carboxyl groups (-COOH) attached to a four-carbon chain.

• In the given options:
• Option 1: Glutaric acid – This is a different dicarboxylic acid with five carbon atoms (HOOC-(CH2)3-COOH).
• Option 2: Adipic acid – This is another dicarboxylic acid with six carbon atoms (HOOC-(CH2)4-COOH).
• Option 3: Succinic acid – This is the common name for butanedioic acid (HOOC-CH2-CH2-COOH).
• Option 4: Malonic acid – This is a dicarboxylic acid with three carbon atoms (HOOC-CH2-COOH).
• The correct match for butanedioic acid is Succinic acid

Therefore, the common name of butanedioic acid is succinic acid.

CONCEPT:

Oxidation of Alcohols

• Oxidation of alcohols is a process where the hydroxyl group (-OH) is converted into a carbonyl group (C=O).
• Primary alcohols can be oxidized to aldehydes, and secondary alcohols can be oxidized to ketones.
• Cyclohexanol is a secondary alcohol, and its oxidation will result in the formation of cyclohexanone.

EXPLANATION:

• The transformation of cyclohexanol to cyclohexanone involves the oxidation of the secondary alcohol to a ketone.
• Several reagents can be used for this oxidation:
• Anhydrous CrO₃ (Chromium trioxide) - A strong oxidizing agent that can oxidize secondary alcohols to ketones.
• PCC (Pyridinium chlorochromate) - A mild oxidizing agent suitable for oxidizing secondary alcohols to ketones without over-oxidation.
• Diisobutylaluminum hydride (DIBAL-H) - Typically used for the reduction of esters and nitriles, not for the oxidation of alcohols.
• O₃/H₂O - Zn dust (Ozonolysis) - Used for oxidative cleavage of alkenes, not for the oxidation of alcohols.
• Among the given options, Anhydrous CrO₃ (Option 1) is the most appropriate reagent for the oxidation of cyclohexanol to cyclohexanone.

Therefore, the correct reagent to bring about the transformation of cyclohexanol to cyclohexanone is Anhydrous CrO₃ (Option 1).

CONCEPT:

Charles's Law

• Charles's law states that the volume of an ideal gas is directly proportional to its absolute temperature, provided the pressure and the amount of gas are held constant.
• The mathematical expression for Charles's law is:

V ∝ T (at constant pressure and amount of gas)

• This means that if the temperature of a gas increases, its volume increases proportionally, and vice versa.

EXPLANATION:

• In a volume vs temperature graph for Charles's law, each line is called an isobar.
• An isochore represents a constant volume process, where the volume of the gas does not change.
• Other terms such as isotopes, isotones, and isobars are not related to this concept:
• Isotopes are atoms of the same element with different numbers of neutrons.
• Isotones are nuclides having the same number of neutrons but different numbers of protons.

Therefore, the correct answer is isobars.

CONCEPT:

Electronic Configuration

• The electronic configuration of an element describes the distribution of electrons in the atomic orbitals.
• Copper (Cu) has an atomic number of 29, which means it has 29 electrons.
• According to the Aufbau principle, electrons are filled in the order of increasing energy levels (1s, 2s, 2p, 3s, etc.).
• However, due to increased stability associated with a fully filled or half-filled d-subshell, copper exhibits an exception to the typical filling order.

EXPLANATION:

• The typical filling order for elements leads to the configuration 3d⁹ 4s² for copper.
• However, copper's actual electronic configuration is 3d¹⁰ 4s¹ because a completely filled d-subshell (3d10) is more stable than a partially filled one (3d9).
• This stability arises due to the exchange energy and symmetric distribution of electrons in the subshell.
• Therefore, one electron from the 4s orbital is promoted to the 3d orbital to achieve a more stable configuration.

Therefore, the electronic configuration of copper (Cu) is 3d¹⁰4s¹.

CONCEPT:

Preparation of Alcohols

• Alcohols can be prepared by various methods, including:
• Acid Catalysed Hydration:
• In this method, alkenes react with water in the presence of an acid catalyst to form alcohols.
• For example, ethene reacts with water in the presence of sulfuric acid to form ethanol.

C₂H₄ + H₂O → C₂H₅OH

• Reduction of Carboxylic Acids:
• Carboxylic acids can be reduced to primary alcohols using strong reducing agents like lithium aluminium hydride (LiAlH₄).
• For example, ethanoic acid can be reduced to ethanol.

CH₃COOH + 4[H] → CH₃CH₂OH + H₂O

EXPLANATION:

• In the given question, two methods of preparation of alcohols are mentioned:

• Statement I: By acid catalysed hydration

• This statement is correct as alcohols can be prepared by the hydration of alkenes in the presence of an acid catalyst.

• Statement II: By reduction of carboxylic acids

• This statement is also correct as carboxylic acids can be reduced to primary alcohols using strong reducing agents like LiAlH₄.

Since both methods mentioned are correct, the correct answer is Both I and II

CONCEPT:

Rate Law (Rate Equation or Rate Expression)

• The rate law (also known as the rate equation or rate expression) expresses the relationship between the rate of a chemical reaction and the concentration of its reactants.
• The general form of the rate law for a reaction aA + bB → cC + dD is:

Rate = k[A]]m[B]]n

• Where:
• Rate is the reaction rate.
• k is the rate constant.
• [A] and [B] are the concentrations of the reactants A and B.
• m and n are the reaction orders with respect to reactants A and B.

EXPLANATION:

• The rate law is also known as the rate equation or rate expression.
• Both terms, rate equation and rate expression, are used interchangeably to describe the mathematical relationship that defines the rate of a reaction.
• Therefore, the correct answer is that another name for the rate law is both the rate equation and the rate expression.

Therefore, the correct answer is Both I and II.