CBSE 2019 sample question paper for Chemistry: Attempt these questions to practise for board exams

CBSE boards and other state board exams are round the corner. With just few days left for the board exams to start, it is time to revise and attempt mock tests. HT will bring to you sample papers of major subjects for your practice, daily for the next few days. These questions are prepared by experts.

CLASS 12 PHYSICAL CHEMISTRY SAMPLE PAPER

Check chemistry sample paper for board exams here (AFP)

Q1.If NaCl is doped with 10-3 mol % of SrCl2 . What is the concentration of Cation Vacancies? (2)

Q2. Copper Crystal has a fcc lattice structure. Atomic radius of copper atom is 128pm.

a.Calculate length of the side of the unit cell ?

b.How many unit cells are there in 1.00cm3

( Atomic mass of copper is 63.5u)(3)

Q3. Will the elevation in boiling point be same if 0.1 mol of Sodium chloride or 0.1 mol of sugar is dissolved in 1L of water? Explain. (2)

Q4. The following curve is obtained when molar conductivity is plotted against the square root of concentration, c1/2 for two electrolytes A and B (2)

a.How do you account for the increase in the molar conductivity of the electrolyte A on dilution.

b.How can you obtain limiting molar conductivity be obtained?

Q5. Calculate the boiling point of a 1M aqueous solution (density 1.04 g mL-1) of Potassium chloride

(Kb for water = 0.52 K kg mol-1, Atomic masses: K=39u, Cl=39.9u) Assume, Potassium chloride is completely dissociated in solution. (3)

Q6. A galvanic cell consists of a metallic zinc plate immersed in 0.1M Zn(NO3)2 solution and metallic plate of lead in 0.02M Pb(NO3)2 solution. Calculate the EMF of the cell. Write the chemical equation for the electrode reactions and represent the cell. (3)

(Given: EoZn2 /Zn =- 0.76V ;EoPb2 /Pb = -0.13V )

Q7. For a first order reaction, show that the time required for 75%. completion of a first order reaction is twice the time required for the completion of 50%. (2)

Q8.The rate of reaction quadruples when the temperature changes from 293 k to 313 K Calculate the energy of activation of the reaction. What is the effect of catalyst on activation energy . (2+1)

Q9. Account for the following : (3)

(a)What happens when a freshly precipitated Fe (OH)3 is shaken with a little amount of dilute solution of FeCl3?

(b)When a beam of light is passed through a colloidal solution , path of beam gets illuminated .

(c)lyophilic colloidal sols more stable than lyophobic colloidal sols?

Q10. Discuss the effect of pressure and temperature on the adsorption of gases on solids. (3)

(The questions given here are provided by individual expert. The author is Abha Choudhary, a teacher of Notre Dame Academy, Patna. Answers will be provided shortly. Hindustan Times does not take any responsibility for the questions or the answers.)