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Board : Air Force Golden Jubilee Institute
Exam : CBSE Class XII Chemistry
Document type : Sample Question Paper
Website : afgji.org

Download Sample/ Model Question Papers :https://www.pdfquestion.in/uploads/6123-Chemistry.pdf

CBSE Chemistry Question Paper

CHEMISTRY
CLASS – XII (2014 – 2015)

Related : Air Force Golden Jubilee Institute CBSE Class XII Computer Science Question Paper : www.pdfquestion.in/6122.html

Time Allowed : 3 hr
Maximum marks: 70

General Instructions

(a) All questions are compulsory.
(b) Q.no. 1 to 5 are very short answer questions and carry 1 mark each.
(c) Q.no. 6 to 10 are short answer questions and carry 2 marks each.
(d) Q.no. 11 to 22 are also short answer questions and carry 3 marks each
(e) Q.no. 23 is a value based question and carry 4 marks.
(f) Q.no. 24 to 26 are long answer questions and carry 5 marks each
(g) Use log tables if necessary, use of calculators is not allowed.

Sample Questions

1. The following figure shows the variation of adsorption of N2 on charcoal with pressure at different constant temperatures: Arrange the temperatures T1, T2 and T3 in the increasing order.

2. Give the formula of a noble gas species which is isostructural with IBr2
3. What is the effect of synergic bonding interactions in a metal carbonyl complex?
4. PCl5 acts as an oxidizing agent. Justify.

5. Write the name of the product formed when benzenediazonium chloride solution is treated with potassium iodide.
6. Name the crystal defect which reduces the density of an ionic solid? What type of ionic substances show this defect?

7. The molar conductivity ( m λ ) of KCl solutions at different concentrations at 298 K is plotted as shown in the figure given below: Determine the value of 0 m λ and A for KCl.
8. Aluminum crystallizes in anfcc structure. Atomic radius of the metal is 125 pm. What is the length of the side of the unit cell of the metal?

9. Draw the structure of the following compounds :
(i) H2S2O7
(ii) XeOF4
OR

Write balanced chemical equations for the following :
(i) Reaction of chlorine with hot and concentrated NaOH.
(ii) Sulphur dioxide is passed through an aqueous solution of Fe (III) salt.
10. 0.5 g of KCl was dissolved in 100 g of water and the solution originally at 200C, froze at -0.240C. Calculate the percentage dissociation of the salt. (Given :Kf for water = 1.86 K kg /mol, Atomic mass: K = 39 u, Cl= 35.5 u)

11. State briefly the principles involved in the following operations in metallurgy. Give an example.
(i) Hydraulic washing.
(ii) Zone refining.

12. i) What type of deviation from Raoult’s law is observed, when two volatile liquids A and B on mixing produce a warm solution? Explain with the help of a well labeled vapour pressure graph.

ii) Consider separate solutions of 0.5 M CH3OH, 0.250 M KCl (aq) and 0.125 M Na3PO4 (aq). Arrange the above solutions in the increasing order of their Van’t Hoff factor.

13. Write the Nernst equationand calculate the emffor the following cell at 298 K: Mg(s) / Mg2+ (0.001 M) // Cu2+ (0.0001 M) / Cu(s) How does Ecellvary with the concentration of both Mg2+ and Cu2+ ions? (GivenEo cell= 2.71 V)

14. Explain the following observations giving appropriate reasons :
(i) Ozone is thermodynamically unstable with respect to oxygen. .
(ii) The HEH bond angle of the hydrides of group 15 elements decrease as we move down the group.
(iii) Bleaching effect of chlorine is permanent.

15. (i) Predict the number of unpaired electrons in the tetrahedral [MnBr4]2- ion.
(ii) Draw structures of geometrical isomers of [Co(NH3)4Cl2]+.
(iii) Write the formula for the following coordinate compound: Amminebromidochloridonitrito-N-platinate(II)

16. Explain what is observed when
(i) Silver nitrate solution is added to potassium iodide solution.
(ii) The size of the finest gold sol particles increases in the gold sol.
(iii) Two oppositely charged sols are mixed in almost equal proportions.

17. (i) In the following pairs of halogen compounds, which would undergo SN1 reaction faster? Explain. and Cl
(ii) Amongst the isomeric dihalobenzenes which isomer has the highest melting point and why?
(iii) Arrange the following haloalkanes in the increasing order of density. Justify your answer.