MHT CET Chemistry Flashcards

24 sample cards from the Chemistry deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

1. Define a ligand and distinguish monodentate from bidentate ligands with examples.

   A ligand is an ion/molecule that donates a lone pair to the central metal. Monodentate donates through one atom (e.g., NH3, Cl⁻); bidentate through two (e.g., ethylenediamine 'en', oxalate).

2. State Werner's definition of primary and secondary valency in coordination compounds.

   Primary valency = oxidation number (ionisable, satisfied by negative ions); secondary valency = coordination number (non-ionisable, satisfied by ligands, fixed and directional).

3. What is the coordination number and write the IUPAC name of K4[Fe(CN)6].

   Coordination number = 6. IUPAC name: potassium hexacyanoferrate(II).

4. According to crystal field theory, what is the splitting pattern of d-orbitals in an octahedral field?

   The five d-orbitals split into lower-energy t2g (dxy, dyz, dzx) and higher-energy eg (dx²−y², dz²); the energy gap is Δo (crystal field splitting energy).

5. What is the difference between froth flotation and magnetic separation in ore concentration?

   Froth flotation concentrates sulphide ores using the differential wettability of ore and gangue with oil/water. Magnetic separation separates magnetic ore particles from non-magnetic gangue (or vice versa) using a magnet.

6. Define roasting and calcination in metallurgy.

   Roasting: heating a sulphide ore strongly in excess air to convert it to oxide. Calcination: heating a carbonate/hydroxide ore in limited or no air to convert it to oxide (removing volatile matter/water).

7. What is the role of an Ellingham diagram in metallurgy?

   It plots ΔG° vs temperature for formation of metal oxides; it helps choose a suitable reducing agent and the temperature at which reduction of a metal oxide becomes feasible (ΔG° negative).

8. State Markovnikov's rule for addition of HX to an unsymmetrical alkene.

   In the addition of a protic acid HX to an unsymmetrical alkene, the negative part (X) attaches to the carbon bearing fewer hydrogen atoms; H adds to the carbon with more hydrogens (via the more stable carbocation).

9. What is the peroxide (Kharasch) effect?

   In the presence of organic peroxides, addition of HBr to an unsymmetrical alkene occurs anti-Markovnikov (Br adds to the carbon with more H atoms) via a free-radical mechanism. Applies only to HBr.

10. Compare the reactivity of SN1 and SN2 reactions with respect to substrate structure.

    SN1 is favoured by 3° (tertiary) halides (stable carbocation, two-step, racemisation); SN2 is favoured by 1° (primary) halides (one-step, backside attack, inversion of configuration).

11. What is the Wurtz reaction and the Fittig reaction?

    Wurtz reaction: 2 R–X + 2Na → R–R + 2NaX (forms higher alkanes). Fittig reaction is the analogous coupling of aryl halides with sodium to give biaryls (Wurtz–Fittig couples aryl + alkyl halides).

12. Distinguish primary, secondary, and tertiary alcohols and the reagent (Lucas test) used.

    Based on the carbon bearing –OH: 1° has one C, 2° has two, 3° has three carbon attachments. Lucas reagent (conc. HCl + anhydrous ZnCl2): 3° reacts immediately (turbidity), 2° in ~5 min, 1° no reaction at room temperature.

13. Why is phenol acidic and how does its acidity compare with alcohols and carboxylic acids?

    Phenol is acidic because the phenoxide ion is resonance-stabilised. Acidity order: carboxylic acid > phenol > water > alcohol.

14. What is Williamson's ether synthesis?

    Preparation of ethers by reacting an alkyl halide with sodium alkoxide (SN2): R–ONa + R'–X → R–O–R' + NaX. Best with primary alkyl halides to avoid elimination.

15. Distinguish aldehydes and ketones using Tollens' and Fehling's tests.

    Aldehydes reduce Tollens' reagent (give silver mirror) and Fehling's solution (red ppt of Cu2O); ketones do not (except α-hydroxy ketones). This distinguishes aldehydes from ketones.

16. What is the aldol condensation reaction?

    Two molecules of an aldehyde/ketone containing α-hydrogen, in the presence of dilute base, combine to give a β-hydroxy aldehyde/ketone (aldol), which on heating loses water to give an α,β-unsaturated carbonyl compound.

17. Compare the basic strength of ammonia, primary, secondary, and tertiary aliphatic amines in the gas phase / general trend in aqueous solution.

    In aqueous solution (due to +I effect, steric and solvation factors) the order is generally 2° > 1° > 3° > NH3 (for methyl amines: (CH3)2NH > CH3NH2 > (CH3)3N > NH3).

18. What is the carbylamine reaction and what is it used to test?

    Primary amines (and only primary, aliphatic or aromatic) react with chloroform and alcoholic KOH to form foul-smelling isocyanides (carbylamines): R–NH2 + CHCl3 + 3KOH → R–NC + 3KCl + 3H2O. A test for 1° amines.

19. What are the products of the diazotisation reaction and the conditions required?

    Aromatic primary amines react with nitrous acid (NaNO2 + HCl) at 0–5°C to form diazonium salts (Ar–N2⁺Cl⁻). Low temperature is needed because diazonium salts are unstable at higher temperatures.

20. Classify monosaccharides, disaccharides, and give one example of each.

    Monosaccharide: simplest sugar, e.g., glucose, fructose. Disaccharide: two monosaccharide units, e.g., sucrose, maltose, lactose. Polysaccharide: many units, e.g., starch, cellulose.

21. What is a peptide bond and a zwitterion in the context of amino acids?

    A peptide bond is the –CO–NH– (amide) linkage between the carboxyl of one amino acid and the amino group of another. A zwitterion is the dipolar form of an amino acid having both –NH3⁺ and –COO⁻ (net charge zero).

22. Distinguish DNA and RNA in terms of sugar and one base difference.

    DNA contains deoxyribose sugar and the base thymine (T); RNA contains ribose sugar and uracil (U) instead of thymine. DNA is usually double-stranded, RNA single-stranded.

23. Differentiate addition and condensation polymers with one example each.

    Addition polymers form by repeated addition of monomers with no loss of small molecules (e.g., polythene, PVC). Condensation polymers form with elimination of small molecules like water (e.g., nylon-6,6, terylene/dacron).

24. State the twelve principles theme of green chemistry and give one example.

    Green chemistry aims to design processes/products that reduce or eliminate use and generation of hazardous substances (atom economy, safer solvents, less waste, renewable feedstocks). Example: using H2O2 instead of chlorine for bleaching, or dry-cleaning with liquid CO2 instead of tetrachloroethene.

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