(i) All questions are compulsory.
(ii) Q. no. 1 to 5 are very short answer questions and carry 1 mark each.
(iii) Q. no. 6 to 10 are short answer questions and carry 2 marks each.
(iv) Q. no. 11 to 22 are also short answer questions and carry 3 marks each.
(v) Q. no. 23 is a value based question and carry 4 marks.
(vi) Q. no. 24 to 26 are long answer questions and carry 5 marks each.
(vii) Use log tables if necessary, use of calculators is not allowed.
- Q1VIEW SOLUTION
- Q2VIEW SOLUTION
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A 10% solution (by mass) of sucrose in water has freezing point of 269.15 K. Calculate the freezing point of 10% glucose in water, if freezing point of pure water is 273.15 K. (3)
Given : (Molar mass of sucrose = 342 g mol−1)(Molar mass of glucose = 180 g mol−1)VIEW SOLUTION
(a) Calculate the mass of Ag deposited at cathode when a current of 2 amperes was passed through a solution of AgNO3 for 15 minutes. (3)VIEW SOLUTION
(Given : Molar mass of Ag = 108 g mol−1 lF = 96500 C mol−1)
(b) Define fuel cell.
(i) What type of isomerism is shown by the complex [Co(NH3)6] [Cr(CN)6]? (3)VIEW SOLUTION
(ii) Why a solution of [Ni(H2O)6]2+ is green while a solution of [Ni(CN)4]2− is colourless? (At. no. of Ni = 28)
(iii) Write the IUPAC name of the following complex : [Co(NH3)5(CO3)]Cl.
- Q14VIEW SOLUTION
Following data are obtained for reaction : (3)
N2O5 → 2NO2 + 1/2O2
t/s 0 300 600 [N2O5]/mol L–1 1.6 × 10–2 0.8 × 10–2 0.4 × 10–2
(a) Show that it follows first order reaction.
(b) Calculate the half-life.VIEW SOLUTION
(Given log 2 = 0.3010, log 4 = 0.6021)
Following compounds are given to you : (3)VIEW SOLUTION
2-Bromopentane, 2-Bromo-2-methylbutane, 1-Bromopentane
(i) Write the compound which is most reactive towards SN2 reaction.
(ii) Write the compound which is optically active.
(iii) Write the compound which is most reactive towards β-elimination reaction.
(a) Write the principle of method used for the refining of germanium. (3)VIEW SOLUTION
(b) Out of PbS and PbCO3 (ores of lead), which one is concentrated by froth floatation process preferably?
(c) What is the significance of leaching in the extraction of aluminium?
Write structures of compounds A, B and C in each of the following reactions: (3)
Do the following conversions in not more than two steps :
(i) Benzoic acid to benzaldehyde
(ii) Ethyl benzene to Benzoic acid
(iii) Propanone to Propene VIEW SOLUTION
- Q19VIEW SOLUTION
- Q20VIEW SOLUTION
- Q21VIEW SOLUTION
Give reasons : (1 × 3 = 3)VIEW SOLUTION
(i) Acetylation of aniline reduces its activation effect.
(ii) CH3NH2 is more basic than C6H5NH2.
(iii) Although –NH2 is o/p directing group, yet aniline on nitration gives a significant amount of m-nitroaniline.
After watching a programme on TV about the presence of carcinogens (cancer causing agents) Potassium bromate and Potassium iodate in bread and other bakery products, Ritu a class XII student decided to aware others about the adverse effects of these carcinogens in foods. She consultanted the school principal and requested him to instruct canteen contractor to stop selling sandwiches, pizza, burgers and other bakery products to the students. Principal took an immediate action and instructed the canteen contractor to replace the bakery products with some proteins and vitamins rich food like fruits, salads, sprouts etc. The decision was welcomed by the parents and students.VIEW SOLUTION
After reading the above passage, answer the following questions: (4)
(i) What are the values (at least two) displayed by Ritu?
(ii) Which polysaccharide component of carbohydrates is commonly present in bread?
(iii) Write the two types of secondary structure of proteins.
(iv) Give two examples of water soluble vitamins.
(a) Account for the following : (3 + 2 = 5)(i) Transition metals form large number of complex compounds.(b) Write one similarity and one difference between the chemistry of lanthanoid and actinoid elements.
(ii) The lowest oxide of transition metal is basic whereas the highest oxide is amphoteric or acidic.
(iii) E° value for the Mn3+/Mn2+ couple is highly positive (+1.57 V) as compare to Cr3+/Cr2+.OR(a) (i) How is the variability in oxidation states of transition metals different from that of the p-block elements? (3 + 2 = 5)(ii) Out of Cu+ and Cu2+, which ion is unstable in aqueous solution and why?
(iii) Orange colour of Cr2O72– ion changes to yellow when treated with an alkali. Why?(b) Chemistry of actinoids is complicated as compared to lanthanoids. Give two reasons.VIEW SOLUTION
(a) An element has atomic mass 93 g mol–1 and density 11.5 g cm–3. If the edge length of its unit cell is 300 pm, identify the type of unit cell. (2 + 3 = 5)
(b) Write any two differences between amorphous solids and crystalline solids.
(a) Calculate the number of unit cells in 8.1 g of aluminium if it crystallizes in a f.c.c. structure. (Atomic mass of Al = 27 g mol–1)
(b) Give reasons:
(i) In stoichiometric defects, NaCl exhibits Schottky defect and not Frenkel defect.
(ii) Silicon on doping with Phosphorous forms n-type semiconductor.
(iii) Ferrimagnetic substances show better magnetism than antiferromagnetic substances. VIEW SOLUTION
(a) Write the product(s) in the following reactions : (5)
(b) Give simple chemical tests to distinguish between the following pairs of compounds :
(i) Ethanol and Phenol
(ii) Propanol and 2-methylpropan-2-olOR
(a) Write the formula of reagents used in the following reactions :
(i) Bromination of phenol to 2,4,6-tribromophenol
(ii) Hydroboration of propene and then oxidation to propanol.
(b) Arrange the following compound groups in the increasing order of their property indicated :
(i) p-nitrophenol, ethanol, phenol (acidic character)
(ii) Propanol, Propane, Propanal (boiling point)
(c) Write the mechanism (using curved arrow notation) of the following reaction :
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