question_answer9) (i) Why are haloalkanes more reactive towards nucleophilic substitution reactions than haloarenes? (ii) Which one of the following two substances undergoes Syl reaction faster and why? Or Write the structures and names of the compounds formed when compound A with molecular formula is treated with the presence of . View Answer play_arrow
question_answer10) Aspirin and phenacetin are analgesics. Aspirin is pain reliever. It was never used alone but it had been used in APC tablets (combination of aspirin, phenacetin and caffeine) for curing common cough and. cold. The use of phenacetin was claimed to produce a sense of relaxation, to reduce tension and to increase work capacity. It was considered to be habit forming, overdose ofwhich may lead to kidney damage. Answer the following question based on the above passage- Identify A to E in the synthesis of E (phenacetin). View Answer play_arrow
question_answer17) Two half reactions of an electrochemical cell are given below Construct the redox equation from the standard potential of the cell and predict if the reaction is reactsnt favoured or product favoured. View Answer play_arrow
question_answer19) A sample of iron (II) oxide has actual formula. In this sample what fraction of metal ions are ions? What type of non-stoichiometric defect is present in this sample? Or Niobium crystallises in body csnered cubic structure. If density is 8.55 . Calculate the atomic radius of niobium using its atomic mass 93 u. View Answer play_arrow
question_answer22) (a) The chemistry of corrosion of iron is essentially an electrochemical phenomenon. Explain the reactions occurring during the corrosion of iron in the atmosphere. (b) Express the relation between conductivity and molar conductivity of a solution held in a cell.View Answer play_arrow
question_answer23) (i) What is the basicity of phosphorous acid and why? (ii) fumes in moist air. Explain. (iii) In preparation of fluorine by electrolysis of anode and cathode are kept separated by a diaphragm of teflon. Why?View Answer play_arrow
question_answer24) Explain the following observations. (i) Why are powders substance more effective adsorbents than crystalline forms? (ii) Why is ester hydrolysis slow in the beginning but becomes faster after some time? (iii) What happens when Fe(OH)3 sol is mixed withView Answer play_arrow
question_answer27) Explain the following observations. (i) Many of the transition elements are known to form interstitial compounds. (i) There is general increase in density from titanium (Z =22) to copper (Z =29). (iii) The members of the actinide series exhibit a larger number of oxidation states than the corresponding members of the lanthanide series. [3 x 1]View Answer play_arrow
question_answer28) Explain the following observations. (i) Nitrogen is much less reactive than phosphorus. (ii) Despite having greater polarity, hydrogen fluoride boils at a lower temperature than water. (iii) Sulphur has greater tendency for catenation than oxygen in the same group. (b) Draw the structures of the following molecules. (i) (ii) [3 + 2] Or (a) Explain the following observations. (i)is more acidic than (ii) Fluorine does not exhibit any positive oxidation state. (iii) Helium forms no real chemical compound. (b) Draw the structures of the following molecules. (i) (ii) [3 + 2 ]View Answer play_arrow
question_answer29) An organic compound (A) with molecular formula forms an orange red precipitate with 2, 4-DNP reagent and gives yellow precipitate on heating with iodine in the presence of sodium hydroxide. It neither reduces Tollen's or Fehling's reagent, nor does it decolorize bromine water or Baeyer's reagent. On drastic oxidation with chromic acid, it gives a carboxylic acid (B) having molecular formula . Identify the compounds (A) and (5) and explain the reactions involved.  (b) Write chemical reactions to affect the following transformations. (i) Cyclohexene to adipic acid. (ii) 3-bromonitrobenzene to 3-nitrobenzoic acid.  Or (a) Write down the functional isomers of a carbonyl compound with molecular formula . Which isomer will react faster with HCN and why ? Explain the mechanism of the reaction also. Will reaction lead to the completion with the conversion of whole reactant into product at reaction conditions. If a strong acid is added to the reaction mixture what will be the affect on concentration of the product and why?  (b) Arrange the following in decreasing order of their acidic strength and give reason for your answer.View Answer play_arrow
question_answer30) Express clearly what you understand by 'rate expression' and 'rate constant' of a reaction?  (b) Nitrogen pent oxide decomposes according to the equation This first order reaction was allowed to proceed at 40?C and the data given below were collected.
|0.400 0.289 0.209 0.151 0.109||0.00 20.00 40.00 60.00 80.00|
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