(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
- Q3VIEW SOLUTION
- Q4VIEW SOLUTION
- Q5VIEW SOLUTION
- Q6VIEW SOLUTION
- Q7VIEW SOLUTION
(a) Arrange the following compounds in the increasing order of their acid strength: (2)
p-cresol, p-nitrophenol, phenol
(b) Write the mechanism (using curved arrow notation) of the following reaction:
Write the structures of the products when Butan-2-ol reacts with the following:
(b) SOCl2 VIEW SOLUTION
- Q9VIEW SOLUTION
- Q10VIEW SOLUTION
(a) What type of isomerism is shown by the complex [Co(NH3)5(SCN)]2+? (3)VIEW SOLUTION
(b) Why is [NiCl4]2− paramagnetic while [Ni(CN)4]2− is diamagnetic? (Atomic number of Ni = 28)
(c) Why are low spin tetrahedral complexes rarely observed?
Write one difference in each of the following: (3)
(a) Multimolecular colloid and Associated colloid
(b) Coagulation and Peptization
(c) Homogeneous catalysis and Heterogeneous catalysis
(a) Write the dispersed phase and dispersion medium of milk.
(b) Write one similarity between physisorption and chemisorption.
(c) Write the chemical method by which Fe(OH)3 sol is prepared from FeCl3. VIEW SOLUTION
(a) The cell in which the following reaction occurs: (3)VIEW SOLUTION
has = 0·236 V at 298 K. Calculate the standard Gibbs energy of the cell reaction. (Given : 1 F = 96,500 C mol−1)
(b) How many electrons flow through a metllic wire if a current of 0·5 A is passed for 2 hours? (Given : 1 F = 96,500 C mol−1)
(a) Based on the nature of intermolecular forces, classify the following solids: (3)
Sodium sulphate, Hydrogen
(b) What happens when CdCl2 is doped with AgCl?
(c) Why do ferrimagnetic substances show better magnetism than antiferromagnetic substances? VIEW SOLUTION
(a) Write the principle of electrolytic refining. (3)VIEW SOLUTION
(b) Why does copper obtained in the extraction from copper pyrites have a blistered appearance?
(c) What is the role of depressants in the froth floatation process?
- Q16VIEW SOLUTION
Give reasons for the following: (3)VIEW SOLUTION
(a) Acetylation of aniline reduces its activation effect.
(b) CH3NH2 is more basis than C6H5NH2.
(c) Although − NH2 is o/p directing group, yet aniline on nitration gives a significant amount of m-nitroaniline.
- Q18VIEW SOLUTION
- Q19VIEW SOLUTION
- Q20VIEW SOLUTION
The following compounds are given to you: (3)VIEW SOLUTION
2-Bromopentane, 2-Bromo-2-methylbutane, 1-Bromopentane
(a) Write the compound which is most reactive towards SN2 reaction.
(b) Write the compounds which is optically active.
(c) Write the compounds which is most reactive towards β-elimination reaction.
- Q22VIEW SOLUTION
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, Rupali a Class XII student decided to make others aware about the adverse effects of these carcinogens in foods. She consulted the school principal and requested him to instruct the canteen contractor to stop selling sandwiches, pizzas, burgers and other bakery products to the students. The principal took an immediate action and instructed the canteen contractor to replace the bakery products with some protein and vitamin rich food like fruits, salads, sprouts, ets. The decision was welcomed by the parents and the students. (4)VIEW SOLUTION
After reading the above passage, answer the following questions:
(a) What are the values (at least two) displayed by Rupali?
(b) Which polysaccharide component of carbohydrates is commonly present in bread?
(c) Write the two type of secondary structures of proteins.
(d) Give two examples of water soluble vitamins.
(a) Write the product(s) in the following reactions: (5)
(b) Give simple chemical tests to distinguish between the following pairs of compounds:(i) Butanal and Butan-2-one
(ii) Benzoic acid and PhenolOR
(a) Write the reaction involved in the following:(i) Etard reaction
(ii) Stephen reduction
(b) How will you convert the following in not more than two steps:(i) Benzoic acid to BenzaldehydeVIEW SOLUTION
(ii) Acetophenone to Benzoic acid
(iii) Ethanoic acid to 2-Hydroxyethanoic acid
(a) Account for the following: (5)
(i) Transition metals show variable oxidation states.
(ii) Zn, Cd and Hg are soft metals.
(iii) Eo value for the Mn3+/Mn2+ couple is highly positive (+ 1·57 V) as compared to Cr3+/Cr2+.
(b) Write one similarity and one difference between the chemistry of lanthanoid and actionoid elements.
(a) Following are the transition metal ions of 3d series:
Ti4+, V2+, Mn3+, Cr3+
(Atomic numbers: Ti = 22, V = 23, Mn = 25, Cr = 24)
Answer the following:
(i) Which ion is most stable in an aqueous solution and why?
(ii) Which ion is a strong oxidising agent and why?
(iii) Which ion is colourless and why?
(b) Complete the following equations:
(ii) VIEW SOLUTION
(a) A 10% solution (by mass) of sucrose in water has a freezing point of 269·15 K. Calculate the freezing point of 10% glucose in water if the freezing point of pure water is 273·15 K. (5)
Given:(Molar mass of sucrose = 342 g mol−1)
(Molar mass of glucose = 180 g mol−1)
(b) Define the following terms:
(i) Molality (m)
(ii) Abnormal molar mass
(a) 30 g of urea (M = 60 g mol−1) is dissolved in 846 g of water. Calculate the vapour pressure of water for this solution if vapour pressure of pure water at 298 K is 23·8 mm Hg.
(b) Write two differences between ideal solutions and non-ideal solutions. VIEW SOLUTION
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