CBSE Sample Paper for Class 11 Chemistry (Solved) – Set C

There is no overall choice in the paper. However, there is n internal choice in one question of 2 marks weight-age, one question of 3 marks weight-age and all t three questions of 5 marks weight age. Please note that the paper given here is only a sample. You can use log table if necessary. Use of calculator is not permitted. Set E of Solved CBSE Sample Paper for Class 11 Chemistry is given below with its solutions.

Sample Question Paper

1. Write de-Broglie expression for wavelength of matter wave. [1]

2. Draw the Lewis dot structure of CO32– ion. [HOTS] [1]

3. What is the value of the gas constant in S.I. units ? [1]

4. Name the type of reactions that occur at cathode in an electrochemical cell. [HOTS] [1]

5. Write the structures of two complex metal hydrides which are used as reducing agent is organic synthesis. [1]

6. What is the S.I. unit of mass ? How is it defined ? [2]

7. An compound on analysis gave the following percentage composition :

K = 31.84%, Cl = 28.98%, 0 = 39.18%

Calculate the empirical formula of the compound. [2]

8. Does the number of moles of reaction products increase, decrease or remain same when each of the following quilibria is subjected to a decrease in pressure by increasing volume ? [2]

(a) PC15(g) ⇔ PC13(g) + C12(g)

(b) Ca0(s) + CO2(g) ⇔ CaCO3(s)

9. What are herbicides ? Give two examples of herbicides. [2]

10. Write IUPAC names of the following compounds : [2]
(a) CH3CH = C(CH3)2 (b) CH2 = CH—C = C—CH3

OR

Explain why the following systems are not aromatic ?

CBSE Sample Paper for Class 11 Chemistry (Solved) - Set C

11. Write s, p, d and f electronic configuration of phosphorus (15), chromium (24) and copper (29). [3]

12. In Millikan’s experiment, static electric charge on the oil drops has been obtained by shining X-rays. If the static electric charge in the oil drop is – 1.282 x 10-18 C, calculate the number of electrons present in it. [3]

13. Write the resonance structures for S03, NO2 and NO3. [3]

14. Consider the reaction :

2S2O32-(aq) + I2(s) -> S4O62-(aq) + 2I(aq)

S2O32-(aq) + 2Br2(/) + 5H2O(l) -> 2SO42-(aq) + 4Br(aq) + 10 H+(aq)

Why does the same reductant, thiosulphate react differerently with iodine and bromine ? [3]

15. Explain the following : [3]

(a) A solution of H2O2 cannot be stored for a long period.

(b) Anhydrous BaO2 cannot be used to prepare H2O2 by reacting with acid.

(c) Liquid hydrogen cannot be used easily as a fuel.

16. Which is expected to have highest boiling point : [3]

NH3, (CH3)3N or PH3 ? Explain why ?

17. If 35.0 cm3 of 0.050 M Ba(NO3)2 are mixed with 25.0 cm3 of 0.020 M NaF, will any BaF2 precipitate ? Ksp of BaF2 is 1.7 x 10-6 at 298K. [HOTS] [3]

18. (a) Which type of intermolecular forces exist between NaCl and H20. [1]

(b) What will be the pressure of the gaseous mixture when 0.5 L of 112 at 0.8 bar and 2.0 L of O2 at 0.7 bar are introduced in a 1 L vessel at 27°C? [2]

19. A large number of fish are suddenly found floating dead on a lake. There is no evidence of toxic dumping but you find an abundance of phytoplankton. Suggest a reason for the fish kill.

20. What happens when : [Give chemical equations] [3]

(1) Propene undergoes ozonolysis.

(2) Ethanol is heated with conc. H2SO4.

(3) Phenol is treated with Zn dust.

21. (1) Write IUPAC name of C6H5CH2CHO and (CH3)2—CH(NH2)–CH2.[1]

(2) Write an example of geometrical isomerism. [1]

(3) What do you mean by resonance energy ? [1]

22. What happens when calcium nitrate is heated ?

Beryllium and magnesium do not give colour to flame whereas other alkaline earth metals do so. Why ? [3]

Or

Describe the importance of the following : [3]

(i) Limestone (ii) Cement

(iii) Plaster of paris.

23. A quantitative measure of the tendency of an element to lose electron is given by its ionization enthalpy. It represents the energy required to remove an electron from an isolated gaseous atom in its ground state. Energy is always required to remove electrons from an atom and hence ionization enthalpies are always positive. The second ionization enthalpy will be higher than the first ionization enthalphy because it is more difficult to remove an electron from a positively charged ion than from a neutral atom.

Now answer the following questions :

(i) Which of the following pairs of elements would you expect to have lower ionisation enthalpy : [2]

(i) Cl or F (ii) Cl or S (iii) K or Ar (iv) Kr or Xe

(ii) The first ionization enthalpy values (in kJ mol-1) of group 13 elements are :

B Al Ga In T1
801 577 579 558 589

How would you explain this deviation from the general trend ? [Value Based Question] [2]

24. (i) What is meant by entropy driven reaction ? How can the reaction with positive change of enthalpy and entropy be made entropy driven ?

(ii) When an ideal gas expands into vacuum, there is neither absorption nor evolution of heat. Why ? [HOTS] [5]

OR

(i) Justify the following statements :

(a) An exothermic reaction is always thermodynamically spontaneous.

(b) The entropy of a substance increases on going from liquid to vapour state at any temperature.

(ii) Why standard entropy of an elementary substance is not zero whereas standard enthalpy of formation is taken as zero ? [HOTS] [5]

25. Indicate the a-and n-bonds in the following molecules : [5]

C6H6, C6H12, C6H12, CH2 = C = CH2, CH3NO3.

OR

Give the IUPAC name of the following compounds :

CBSE Sample Paper for Class 11 Chemistry (Solved) - Set C

26. (a) If the starting material for the manufacture of silicones is RSiC13, write the structure of the product formed. [2]

(b) How is excessive content of CO2 responsible for global warming ? [3]

OR

(a) Suggest reasons why the B-F bond lengths in BF3 (130 pm) and BE4 (143 pm) differ. [2]

(b) Explain structures of diborane and boric acid. [3]

Sample Question Paper Solutions

All CBSE Sample Papers for Class 11 Chemistry Class 11 All Subjects All Classes

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