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

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. What is the maximum number of electrons that can be present in an atom in which the highest principal quantum number is 4? [1]

2. How is bond order related to the stability of a molecule ? [1]

3. What is the binding force between molecules if a substance is a gas under ordinary conditions of temperature and pressure ? [1]

4. In the reaction;

Mn02 + 4HC1 — MnC12 + C12 + 2H20, which species is oxidized ?

5. How many hydrogen bonded water molecule(s) are present in CuSO4.5H20 ? [1]

6. A sample of NaNO3 weighing 0.83 g is placed in a 50 ml volumetric flask. The flask is then filled with water to the mark on the neck. What is the molarity of the solution ? [2]

7. Determine the empirical formula of an oxide of iron which has 69.9% iron and 30.1% dioxygen by mass. [2]

8. Calculate the hydrogen ion concentration in the following biological fluids whose pH are given : [2]

(a) Human muscle-fluid, 6.83

(b) Human stomach fluid, 1.2

9. Write four major water pollutants. [2]

10. Draw the structures of cis- and trans-isomers of the following compounds name ; [2]

(i) CHCI = CHCI

(ii) C2H5C(CH3) = C(CH3)C2H5

OR

Suggest the name of two Lewis acid other than anhydrous aluminium chloride which can be used during ethylation of benzene. [2]

11. Electromagnetic radiation of wavelength 242 nm is just sufficient to ionize the sodium atom. Calculate the ionization energy of sodium in kJ mol-1.

12. Write the electronic configurations of the following ions : [3]

(a) H+,

(b) Na+.

(c) 02-.

13. Define octet rule. Write its significance and limitations. [3]

14. Assign oxidation number to the underlined elements in each of the following species : [3]

(a) Ca02,

(b) NaBH4,

(c) H2S2O7.

15. Anhydrous A1C13 is covalent but A1C13.6H20 is ionic in nature. How would you account for this ? [31

16. (a) Write chemical reaction to show the amphoteric nature of water.

(b) How does H202 behave as a bleaching agent ? [3]

17. (i) A sample of pure PC15 was stored in an evacuated vessels at 473K. After equilibrium was attained, concentration of PC15 was found to be 0.5 x 10-1 mol L-1. If value of Kc. is

8.3 x 10-3, what are the concentration of PC13 and C12 at equilibrium ?

(ii) Give relation between Kp and IQ for above equation.  [3]

18. What will be the pressure of the gas mixture when 0.5 L of H2 at 0.8 bar and 2.0 L of oxygen at 0.7 bar are introduced in a 1 L vessel at 27°C? [3]

19. Explain tropospheric pollution in 100 words. [3]

20. Carry out the following conversions : [3]

(I ) Ethyl alcohol to ethane.

(2) Sodium acetanilide to benzene.

(3) Benzene to nitrobenzene.

21. State the principle of the following techniques taking an example : [3]

(i) Steam Distillation.

(ii) Chromatography.

22. Write chemical equation only for preparation of : [3]

(i) Plaster of Paris,

(ii) Quick lime,

(ii) Slaked lime.

OR

Compare the alkali metals and alkaline earth metals with respect-toionization enthalpy (i) basicity of oxides, and (ii) solubility of hydroxides. [3]

23. The removal of an electron from an atom results in the formation of a cation, whereas gain of an electron leads to an anion. The ionic radii can be estimated by measuring the distances between cations and anions in ionic crystals. A cation is smaller than its parent atom because it has fewer electrons while its nuclear change remains the same. The size of an anion will be larger than that of the parent atom because the addition of one or more electrons would result in increased repulsion among the electrons and a decrease in effective nuclear charge. When we find some atoms and ions which contain the same number of electrons, we call them isoelectronic species.

Now answer the following questions :

(i) Arrange the following ions in the order to increasing size

Be2+, Cl, Na+, Mg2+

(ii) In which of the following pairs, which species has a larger size ‘? [Value Based Question] [4]

(i) Br or Br, (ii) O2- or F (iii) Li+ or Na+ (iv) P or As.

24. Show that in the isothermal expansion of an ideal gas, AU = 0 and AU = 0.  [5]

OR

Air contain 99% N2 and O2 gases. Then why do not they combine to form NO under the standard conditions ? Give that the standard free energy of formation of NO(g) is 86.7 kj mol-1.  [5]

25. What is the difference between distillation, distillation under reduced pressure and steam distillation? [5]

OR

Explain the terms inductive and electromeric effects. Which electron displacement effect explains the

following correct orders of acidity of the carboxylic acids ? [51

(a) Cl3COOH > C12CHCOOH > C1CH2COOH

(b) CH3CH2COOH > (CH3)2CHCOOH > (CH3)C.COOH

26. (a) Write reactions to justify amphoteric nature of aluminium. [2]

(b) What are electron deficient compounds ? Are BC13 and SiC14 electron deficient species ? Explain. [3] OR

(a) Consider the compounds BC13 and CC14. How will they behave with water ? Justify. [2]

(b) Is boric acid a protic acid ? Explain. [3]

Sample Question Paper Solutions

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

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