A Covalent bond energy
B Lattice energy of ionic compounds
C Ionization energy of metals
D Electron affinity of nonmetals
Explanation: The Born-Haber cycle applies Hess\'s law to calculate lattice energy by combining steps: sublimation, ionization, dissociation, electron affinity, and formation.
A Addition of a diene to an alkene forming a six-membered ring
B Elimination reaction forming a conjugated system
C Nucleophilic substitution on a diene
D Radical polymerization of dienes
Explanation: The Diels-Alder reaction is a [4+2] cycloaddition between a conjugated diene (4 pi electrons) and a dienophile (2 pi electrons), forming a cyclohexene ring.
A K = kf + kr
B K = kf / kr
C K = kr / kf
D K = kf x kr
Explanation: At equilibrium, forward rate equals reverse rate: kf[reactants] = kr[products], so K = [products]/[reactants] = kf/kr.
A Formaldehyde
B Acetaldehyde
C Acetone
D Acetic acid
Explanation: CH3COCH3 (propan-2-one) is commonly known as acetone, the simplest ketone and an important industrial solvent.
A IR spectroscopy
B NMR spectroscopy
C Mass spectrometry
D UV-Vis spectroscopy
Explanation: Mass spectrometry ionizes molecules and measures the mass-to-charge ratio (m/z), providing precise molecular mass and structural fragmentation patterns.
A Ethane
B Ethanal (acetaldehyde)
C Ethanoic acid
D Ethyl acetate
Explanation: Mild oxidation of ethanol with acidified K2Cr2O7 produces ethanal (acetaldehyde). With excess oxidant and heating, it further oxidizes to ethanoic acid.
A Tetrahedral
B Square planar
C Octahedral
D Trigonal bipyramidal
Explanation: d8 metals (like Ni2+, Pd2+, Pt2+) with strong field ligands form square planar complexes because the large crystal field splitting makes this geometry more stable than tetrahedral.
A Temperature and pressure of a gas
B Absorbance to concentration, path length, and molar absorptivity
C Rate of reaction to concentration
D Voltage to current and resistance
Explanation: Beer-Lambert Law states absorbance (A) = molar absorptivity (epsilon) x path length (l) x concentration (c), forming the basis of quantitative UV-Vis analysis.
A Bromination of benzene with Br2/FeBr3
B Chlorobenzene reacting with NaOH at high temperature
C Friedel-Crafts alkylation of benzene
D Nitration of benzene
Explanation: Chlorobenzene reacts with NaOH at high T/pressure (Dow process) via nucleophilic aromatic substitution, where OH- replaces Cl on the aromatic ring.
A Kc = [SO3]^2 / ([SO2]^2 x [O2])
B Kc = [SO2]^2 x [O2] / [SO3]^2
C Kc = [SO3] / ([SO2] x [O2])
D Kc = [SO3]^2 / [SO2]^2
Explanation: Kc = [products]^coefficients / [reactants]^coefficients = [SO3]^2 / ([SO2]^2 x [O2]^1).
A Polyethylene
B Polyvinyl chloride
C Polylactic acid (PLA)
D Polystyrene
Explanation: PLA is a biodegradable polyester derived from lactic acid (from corn starch). Microorganisms can break down its ester linkages in the environment.
A An ester
B An amide (N-methylacetamide)
C A ketone
D An ether
Explanation: CH3NH2 (methylamine) reacts with CH3COOH (ethanoic acid) in a condensation reaction to form N-methylacetamide (CH3CONHCH3) and water.
A Increases K
B Decreases K
C Does not change K
D Makes K zero
Explanation: A catalyst speeds up both forward and reverse reactions equally by lowering activation energy. It helps reach equilibrium faster but does not change the position of equilibrium (K).
A 2-Methylbutanoic acid
B 3-Methylbutanoic acid
C 2-Ethylpropanoic acid
D 2-Methylpentanoic acid
Explanation: The longest chain containing COOH has 4 carbons (butanoic acid). Numbering from COOH, the methyl is on C3, giving 3-methylbutanoic acid.
A s-s overlap
B p-p overlap
C sp-sp overlap
D s-p overlap
Explanation: In H2, each hydrogen has a 1s orbital. The sigma bond is formed by the head-on overlap of these two 1s orbitals (s-s overlap).
A A nitrile
B A cyanohydrin (2-hydroxybutanenitrile)
C An amide
D An oxime
Explanation: HCN adds across the C=O bond of propanal: the CN- attacks the carbonyl carbon and H+ protonates the oxygen, forming a cyanohydrin.
Explanation: In a tetrahedral complex, the metal is surrounded by 4 ligands at the corners of a tetrahedron, giving a coordination number of 4.
A KMnO4
B SOCl2 (thionyl chloride)
C Na2Cr2O7
D NaOH
Explanation: SOCl2 converts alcohols to alkyl chlorides with inversion of configuration (if chiral). The byproducts SO2 and HCl are gases, driving the reaction forward.
A [Ar] 3d4 4s2
B [Ar] 3d5 4s1
C [Ar] 3d6 4s0
D [Ar] 3d3 4s2 4p1
Explanation: Chromium is an exception: one 4s electron promotes to 3d to achieve the extra stability of half-filled d-orbitals, giving [Ar] 3d5 4s1.
A Free radical mechanism coupling alkyl halides
B Nucleophilic substitution
C Electrophilic addition
D Elimination
Explanation: The Wurtz reaction uses sodium metal to couple two alkyl halide molecules via a free radical mechanism: 2R-X + 2Na -> R-R + 2NaX.