Class 12th Chemistry 2017 Set3 Outside Delhi Board Paper Solution
(a) What type of isomerism shown by the complex
[Co(NH3)5 (SCN)]2+ ?
(b) Why is [NiCl4]2- paramegnatic while [Ni(CN)4]2- is diamagnetic?
(Atomic number of Ni = 28)
(c) Why are low spin tetrahedral complexes rarely observed?
(a) This complex is Linkage isomerism
(b) Because Ni[Cl4]2- has 2 unpaired electrons and is Paramagnetic. While Ni[CN4]2- has paired electrons and is Diamagnetic.
(c) There are only 4 ligands in a tetrahedral complex. So,the ligand field is roughly 2/3 of the octahedral field. The direction of DC ligand approach in tetrahedral complex does not coincide with the d-orbitals. This reduces the field by a factor of 2/3. Hence, ∆t is roughly 2/3 x 2/3 = 4/9 of ∆o.
As a result, all tetrahedral complexes are high-spin since the CFSE is normally smaller than the paring energy.
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Give simple chemical tests to distinguish between the following pairs of compounds.
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(ii) Acetophenone and Benzophenone
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(iv) Benzoic acid and Ethyl benzoate
(v) Pentan-2-one and Pentan-3-one
(vi) Benzaldehyde and Acetophenone
(vii) Ethanal and Propanal
- Q:-
How the following conversions can be carried out?
(i) Propene to propan-1-ol
(ii) Ethanol to but-1-yne
(iii) 1-Bromopropane to 2-bromopropane
(iv) Toluene to benzyl alcohol
(v) Benzene to 4-bromonitrobenzene
(vi) Benzyl alcohol to 2-phenylethanoic acid
(vii) Ethanol to propanenitrile
(viii) Aniline to chlorobenzene
(ix) 2-Chlorobutane to 3, 4-dimethylhexane
(x) 2-Methyl-1-propene to 2-chloro-2-methylpropane
(xi) Ethyl chloride to propanoic acid
(xii) But-1-ene to n-butyliodide
(xiii) 2-Chloropropane to 1-propanol
(xiv) Isopropyl alcohol to iodoform
(xv) Chlorobenzene to p-nitrophenol
(xvi) 2-Bromopropane to 1-bromopropane
(xvii) Chloroethane to butane
(xviii) Benzene to diphenyl
(xix) tert-Butyl bromide to isobutyl bromide
(xx) Aniline to phenylisocyanide
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A 5% solution (by mass) of cane sugar in water has freezing point of 271 K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 K.
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A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL-1, then what shall be the molarity of the solution?
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Henry's law constant for CO2 in water is 1.67 x 108Pa at 298 K. Calculate the quantity of CO2in 500 mL of soda water when packed under 2.5 atm CO2 pressure at 298 K.
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Calculate the mass of a non-volatile solute (molar mass 40 g mol-1) which should be dissolved in 114 g octane to reduce its vapour pressure to 80%.
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The vapour pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K. Find out the composition of the liquid mixture if total vapour pressure is 600 mm Hg. Also find the composition of the vapour phase.
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Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.
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If NaCl is doped with 10-3mol % of SrCl2, what is the concentration of cation vacancies?
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A reaction is first order in A and second order in B.
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Write IUPAC names of the following compounds and classify them into primary,secondary and tertiary amines.
(i) (CH3)2 CHNH2
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Name the following compounds according to IUPAC system of nomenclature:
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(iii) CH3CH=CHCHO
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What products would be formed when a nucleotide from DNA containing thymine is hydrolysed?