Theory Examination (Semester-II) 2015-16 ENGINEERING CHEMISTRY

This question paper evaluates understanding of molecular orbital theory, stereochemistry, spectroscopy (UV & NMR), polymer chemistry, water treatment, corrosion science, and organic reaction mechanisms.
It is divided into three sections: short definitions, descriptive answers, and long analytical questions.

SECTION – A (10 × 2 = 20 Marks)

This section contains ten brief questions requiring short explanations or definitions.
Topics include:

Paramagnetic nature of O₂ on the basis of MOT

Isomerism in maleic vs fumaric acids

Chemical shift in NMR

Chromophore & auxochrome in UV spectroscopy

Inductive effect (with examples)

Stability of benzyl vs ethyl carbocation

Reverse osmosis & Calgon treatment

Disadvantages of scale formation

Organic synthesis of propyne/propene type compounds from acetylene

Addition vs condensation polymerisation

This section checks basic conceptual clarity in organic, physical, and environmental chemistry.

SECTION – B (5 × 10 = 50 Marks)

Students must attempt any five medium-length, descriptive answers.
Topics include:

Molecular Orbital diagrams & bond orders of He₂⁺, O₂, NO, HF, N₂

Optical isomerism in molecules with two chiral centres

Beer–Lambert law + calculation of absorptivity & molar absorptivity

Mechanism of SN1 and SN2 reactions

Ion-exchange method for softening of water

Notes on reverse osmosis and boiler corrosion

Galvanization of iron & its corrosion-preventive mechanism

Ziegler–Natta catalyst and its role in polymerization

This section tests theory, chemical calculations, stereochemistry, reaction mechanisms, and industrial chemistry concepts.

SECTION – C (2 × 15 = 30 Marks)

Students must attempt any two long-answer questions.

Topics include:

Corrosion & Hardness

Corrosion inhibitors: anodic vs cathodic

Reasons for expressing hardness as CaCO₃ equivalent + other units

Stereochemistry & Polymers

Enantiomers vs diastereomers

Racemic mixture vs meso compounds

Preparation, properties, and uses of silicone rubber, PMMA, and Bakelite

Spectroscopy & Reaction Kinetics

Principle & applications of NMR in structure elucidation

Derivation of second-order rate law (for two different reactants)

This section evaluates deep problem-solving, chemical reasoning, and advanced conceptual knowledge.