The correct order of relative stability is I > II > III.

Explanation:

• Structure I is the most stable because it is a neutral resonating structure.
• Structure II is less stable due to a positive charge on a less electronegative atom.
• Structure III is the least stable as it has a negative charge on a carbon atom.

The S_N1 mechanism proceeds through carbocation formation, favoring stable intermediates:

• Halide (A): Forms a stabilized allylic carbocation.
• Halide (B): Does not form a stable carbocation.
• Halide (C): Forms a stabilized benzylic carbocation.
• Halide (D): Forms a tertiary carbocation.

Only halide (B) fails to undergo S_N1 due to the lack of a stable intermediate.

When the tin coating is peeled off, iron is exposed and rusts more quickly due to galvanic action. Tin, being less reactive, acts as a cathode, accelerating the rusting of the iron anode.

Elements with d¹⁰ configuration:

• Cu: [Ar] 3d¹⁰ 4s¹
• Zn: [Ar] 3d¹⁰ 4s²
• Ag: [Kr] 4d¹⁰ 5s¹
• Cd: [Kr] 4d¹⁰ 5s²

These elements have fully filled d-orbitals, ensuring stability.

Explanation:

• Phthalein dye test: Identifies phenols via color formation.
• Lucas test: Differentiates alcohols (1°, 2°, 3°).
• Tollen's test: Identifies aldehydes.
• Carbylamine test: Identifies primary amines.

Phenols specifically give positive results in the Phthalein dye test.

The first member of the series is formic acid (HCOOH). The second member, acetic acid (CH₃COOH), has the molecular formula C₂H₄O₂.

Steam distillation is ideal for separating volatile components that are immiscible in water. It is commonly used for essential oil extraction and purification of similar substances.

The reaction sequence involves:

• Step (i): Hydroboration-oxidation (anti-Markovnikov addition) forms Ph-CH₂-CH₂OH.
• Step (ii): Alcohol converted to alkyl halide (Ph-CH₂-CH₂Br).
• Step (iii): Grignard reagent formed (Ph-CH₂-CH₂MgBr).
• Step (iv): Reaction with formaldehyde gives Ph-CH₂-CH₂-CH₂-OH.

Final product: Ph - CH₂ - CH₂ - CH₂ - OH.

Explanation:

• (A): Oxidation of phenol to benzoquinone uses Na₂Cr₂O₇ and H₂SO₄ as oxidizing agents.
• (B): Kolbe's reaction involves carboxylation of phenol using NaOH and CO₂, followed by acidification with HCl.
• (C): Reimer-Tiemann reaction introduces an aldehyde group on the phenol ring using NaOH and CHCl₃.
• (D): Williamson's synthesis prepares ethers by reacting phenoxide with CH₃Cl in the presence of NaOH.

Thus, the correct matching is:

(A)-(IV), (B)-(III), (C)-(I), (D)-(II)

The given reaction involves cleavage of the ether bond using HI. The steps are:

1. Protonation of the ether oxygen atom by HI forms an oxonium ion intermediate.
2. Cleavage of the C--O bond yields cyclohexanol and a tertiary carbocation, (CH₃)₃C⁺.
3. The tertiary carbocation reacts rapidly with I^- to form (CH₃)₃C--I as the final product.

Thus, the major products are cyclohexanol and (CH₃)₃C--I.

The structure of HOCH(CN)₂ consists of:

• A central carbon atom bonded to one hydroxyl group (OH).
• Two cyano groups (CN).

Option (4) accurately represents this structure.

Statement I: Oxygen exhibits other oxidation states such as 0 in O₂ and +1 or +2 in OF₂. Hence, it does not solely exhibit -2 oxidation state.

Statement II: Stability of +4 oxidation state increases down the group due to the inert pair effect, contrary to the claim.

Therefore, both statements are incorrect.

[Co(NH₃)₆]³⁺ exhibits d²sp³ hybridization, forming an octahedral geometry. Other examples include:

• BrF₅: sp³d², square pyramidal.
• [PtCl₄]^2-: dsp², square planar.
• SF₆: sp³d², octahedral.

Thus, only [Co(NH₃)₆]³⁺ demonstrates d²sp³ hybridization.

The intermediate formed with excess NH₃ is a diammonium salt, NH₃-(CH₂)₄-NH₃⁺Cl^-. On reaction with NaOH, it deprotonates to yield 1,4-diaminobutane (H₂N-(CH₂)₄-NH₂).

Explanation:

Molarity is defined as the number of moles of solute per liter of solution. Since the volume of the solution changes with temperature due to thermal expansion or contraction, molarity also changes. Other quantities like mass percentage, molality, and mole fraction are independent of temperature as they depend solely on the ratio of masses or moles.

Explanation:

When egg white is boiled, the protein undergoes denaturation, resulting in the loss of secondary, tertiary, and quaternary structures. However, the primary structure, which is the sequence of amino acids linked by peptide bonds, remains unaffected because these covalent bonds are not broken during denaturation.

Explanation:

Nitrogen in N^3- is in its lowest oxidation state and cannot gain more electrons, so it cannot function as an oxidizing agent. Other species listed can accept electrons and undergo reduction, thus acting as oxidizing agents.

Explanation:

The eclipsed conformation is the least stable due to maximum repulsion between C-H bond electron clouds on adjacent carbons. The staggered conformation is more stable as it minimizes repulsion by keeping bonds as far apart as possible.

Explanation:

The Wacker process uses PdCl₂ as a catalyst, not PtCl₂. The other pairs correctly represent the respective processes or applications.

Explanation:

• Sr²⁺ (Z = 38): Loses two electrons to match [Kr] (krypton).
• Cs⁺ (Z = 55): Loses one electron to match [Xe] (xenon).
• La³⁺ (Z = 57): Loses three electrons to match [Xe].
• Yb²⁺ (Z = 70): Loses two electrons to match [Xe].

Pb²⁺ and Fe²⁺ do not have noble gas configurations. Therefore, the total is 4 ions.

Explanation:

• Non-polar molecules: CO₂ (linear), H₂ (diatomic), CH₄ (tetrahedral), and BF₃ (trigonal planar).
• Other molecules are polar due to asymmetry or electronegativity differences.

Total non-polar molecules: 4.

Explanation:

Using the formula for a first-order reaction:

t = (2.303 / k) log ([A]₀ / [A])

For 99.9% completion, [A] = 0.001[A]₀:

t = (2.303 / k) × 3 = 10 × t_1/2.

Thus, the time required is 10 times the half-life.

Explanation:

The complex contains Pt²⁺ in square planar geometry. With a (d⁸) configuration, all d-electrons pair up, leaving no unpaired electrons.

The magnetic moment is 0 B.M., making it diamagnetic.

Explanation:

ΔG^o = ΔH^o - TΔS^o

Substituting values: ΔG^o = 77.2 × 10³ - (400 × 122) = -28400 J.

Using ΔG^o = -2.303RT log K:

( log K = -28400/-2.303 × 8.314 × 400} ≈ 37.08 ≈ 37 × 10^-1 ).

Explanation:

Molarity (M) is calculated using the formula:

M = n / V, where n is the number of moles and V is the volume in liters.

• Moles of NaOH = mass / molar mass = 84 / 40 = 2.1 moles.
• Volume of solution = n / M = 2.1 / 3 = 0.7 L = 7 × 10^-1 dm³.

Explanation:

The balanced equation for oxidation is:

PbS + 4O₃ → PbSO₄ + 4O₂

Here, 1 mole of PbS reacts with 4 moles of O₃ (X = 4), producing 4 moles of O₂ (Y = 4).

Therefore, X + Y = 4 + 4 = 8.

Explanation:

Using the Nernst equation:

E = E° - (0.059 / n) log (1 / [H⁺])

• E° = 0 (standard hydrogen electrode).
• [H⁺] = 10^-3 M, so log(10^-3) = -3.
• E = -0.059 × (-3) = 0.177 V.

The potential is 0.177 V, or 18 × 10^-2 V.

Explanation:

The reaction is:

C₆H₅NH₂ + CH₃COOCOCH₃ → C₆H₅NHCOCH₃ + CH₃COOH

• Molar mass of aniline = 93 g/mol.
• Moles of aniline = 9.3 / 93 = 0.1 moles.
• Molar mass of acetanilide = 135 g/mol.
• Mass of acetanilide = 0.1 × 135 = 13.5 g = 135 × 10^-1 g.

Explanation:

To identify chiral carbons, look for carbon atoms bonded to four different substituents:

• Compound 1: Second carbon is chiral.
• Compound 2: Third carbon is chiral.
• Compound 3: Second carbon is chiral.
• Compound 4: Third carbon is chiral.
• Compound 5: Second carbon is chiral.

Total chiral compounds: 5.