CBSE Guess > Papers > Important Questions > Class XII > 2013 > Chemistry > Model Paper 1 by Mr. R. Srinivas Vasudevamurthy
CBSE CLASS XII
Model Paper 1
Roll Number Code No: 056/ISG/
Model Paper 1
Time allowed: 3 hrs
XII - CHEMISTRY(Theory)
M.Marks: 70
General Instructions:
1. Answer all the questions.
2. uestion number 1 to 8 carry 1 mark each. Answer them in one word or one sentence each.
3. Question number 9to 18 carry 2 marks each. Answer them in 30 words each.
4. Question number 19 to 27 carry 3 marks each. Answer it in about 40 words each.
5. Question number 28 to 30 carry 5 marks each. Answer them in about 70 words each.
6. Use of calculator not permitted. Use of log table permitted.
1. How does molar conductivity of a strong electrolyte vary with the dilution of electrolyte solution? 1 2. Describe electrophoresis briefly. 1 3. H3PO4 is triprotic acid while H3PO3 is diprotic. Why? 1 4. Calculate the number of tetrahedral voids and octahedral voids in an unit cell of FCC. 1 5. Write the IUPAC name of the compound:
CH3COCH2COOH1 6. Give one example of Swartz reaction. 1 7. Mention two functions of nucleic acid. 1 8. Mention the monomers of the polymer Dacron. 1 9. Account for the following:
a) Mountain climbers sometimes get symptoms of a condition known as anoxia.
b) Calcium chloride is added to clear the roads covered by snow.2 10. Write the equations of the reactions involved at each electrode when an aqueous solution of dilute H2SO4 is electrolysed using Pt electrode.
2 11. Resistance of 0.01M CH3COOH solution is 2220 ohm. Cell constant is 0.366 cm-1.Calculate the degree 2 of dissociation and dissociation constant of CH3COOH at this concentration. Given L0 HCl, NaCl, H3COONa are 425,128 and 96 scm2 mole-1 respectively. 2 12. Complete the following ionic equations: i) Cr2O72- + Fe2+ + H+
ii) MnO4- +C2O42- +H+
2 13. Account for the following: a) Phosphorus shows marked tendency for catenation while nitrogen shows little tendency for catenation.
b) Oxygen has lesser negative value of electron gain enthalpy than Sulphur.2 14. Give one example each of a) Williamson's synthesis
b) Reimer-Tiemann reaction.2 15. Carry out the following conversions: a) Phenol to para bromobenzene.
b) Ethanal to Acetone2 16. Identify the compounds A,B,C and D in the following reaction.
A
B
NaOBr NaNO2+HCl H3O+ Zn dust
273-278K2 17. Give one example each of
a) Gabriel Pthalimide synthesis.
b) Sand Meyer reaction.Distinguish chemically between
a) Dimethlamine and Trimethylamine.
b) Methanamine and Dimethlamine.2 18. Write the equation of the reaction involved in the preparation of Buna-S-rubber. 2 19. Calculate the density of unit cell of NaCl. Given molar mass of NaCl=58.5u. Distance between Na+ and Cl- is 281pm. Avagadro number=6x1023 mole- . What type of defect does NaCl exhibit If the actual density is 1.95 g/cm3 3 20. The vapour pressures of pure liquids A and B are 450 and 700 mm Hg respectively at 350K. Find the composition of liquid mixture if the total pressure is 600 mm Hg. Also find the composition in vapour phase. 3 21. a) Cr2O3 + 2Al
b) Write the reactions involved in the extraction of Fe from heamatite ore.
3 22. a) Give four differences between lyophilic sol and lyophobic sol.
b) Which is more effective in stopping bleeding? FeCl3 or KCl Why?3 23. Using valence bond theory explain the structure and magnetic behavior of [Fe(CN)6]4-
( Atomic number of Fe=26)3 24. An alkyl halide C7H15Br is optically active. It reacts with KOH solution to give racemic mixture. Explain the mechanism of the reaction.
3 25. Account for the following:
a) Transition metals form complexes easily.
b) First ionization enthalpy of early actinoids are lesser than that of early lanthanoids.
c) Of the d4 species Cr2+ is reducing while Mn3+ is oxidizing.3 26. What happens when D-Glucose is treated with
a) HI
b) HNO3
c) Acetic anhydride. Explain the significance of each reaction.3 OR Draw the Howarth structure of sucrose. Is it a reducing or non reducing sugar? Justify your answer. 27. a) While antacids and anti allergic drugs interfere with the function of antihistamine, why they
do not with the function of each other?
b) What are cationic detergents? Give one example of cationic detergent. Mention one use of cationic detergents.3 28. a) Derive the expression for the half life of a zero order reaction.
b) A+5B+6C
Experiment (A) M (B) M (C) M Rate M/minute 1. 0.02 0.02 0.02 00208 2. 0.01 0.02 0.02 0.00104 3. 0.02 0.04 0.02 0.00416 4. 0.02 0.02 0.04 0.00832 5 Determine the order with respect to each reactant. Find K .Calculate the initial rate when concentration of each reactant is 0.01M.Find the initial rate of change in concentrations of B and L
OR a) Mention the factors which affect the rate of a reaction.
b) The following data were obtained during the first order decomposition of SO2Cl2 at constant volume
SO2Cl2(g)
Experiment Time(sec) Total pressure(atm)
1 0 0.5
2 100 0.6
Calculate the rate when total pressure is 0.65 atmospheres.29. a) Account for the following:
i) 2,2,6-Trimethylcyclohexanone is less reactive towards nucleophile than cyclohexanone.
ii) Formaldehyde and benzaldehyde undergoes cannizaro reaction.b) Carry out the following conversions:
i) Benzoic acid to m-nitrobenzoic acid.
ii) Benzoyl chloride to benzaldehyde.
iii) Acetic acid to acetone.5 OR a) An organic compound contain 69.77% Carbon and 11.63% Hydrogen and the remaining
Oxygen. Molecular mass of the compound is 86 u. It does not reduce Tollen’s reagent, gives
positive iodoform test and respond to sodium bisulphate test. On oxidation it gives acetic acid and
propanoic acid. Give the structure of the organic compound.b) Give one example each of
i) Decarboxylation
ii) HVZ reaction30. a) Draw the structures of
i) XeOF4
ii) HClO4
iii) ClF3
b) Complete the following reactions;
i) O3+H2O+I-
ii) XeF6+ KF
5 OR a) Account for the following:
i) P4 is more reactive than N2
ii) Xe forms compounds with fluorine and oxygen.
iii) All the five bonds in PCl5 are not equivalent.b) Draw the structures of
i) SF4
ii) H2S2O7
Submitted By : Mr. R. Srinivas Vasudevamurthy
Email: [email protected]
