Municipality Examination
Chemistry- Grade XI
Examination - 2079 (2022)
Regular Students
Time - 3 hrs
Full Marks - 75
Pass Marks - 27
Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.
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Group 'A'
Circle the best alternative to the following questions (11x1=11)
1. The no. of electrons in Mg2+
a. 12
b. 14
c. 10
d. 0
2. Weight of 11.2 L of O2 gas at NTP is
a. 0 g
b. 22 g
c. 16 g
d. 44 g
3. Which of the following quantum number is different for two electrons in the same orbital?
a. Azimuthal quantum number
b. Magnetic quantum number
c. Spin quantum number
d. Principle quantum number
4. In Mendeleev's periodic table elements are arranged according to their
a. Increasing At. Wt.
b. Increasing At. No.
c. Decreasing At. Wt.
d. Decreasing At. No.
5. Hydrogen bonding is not present in
a. Glycerol
b. Water
c. Hydrogen Sulphide
d. Hydrogen
6. 1 F charge is approximately equal to
a. 1.6 x 10-19 C
b. 96500 C
c. 6.023 x 10-23
c. 6.023 x 10-23
d. 1 C
7. Which of the following is the unit for surface tension?
a. dynes.cm
b. dynes.cm2
c. dynes.cm-2
d.dynes.com-1
8. The molecular formula of Epsom salt is:
a. MgSO4.7H2O
b. CaSO4.2H2O
c. MgO
d. MgCO3
9. The -CHO group as prefix is
a. al
b. Formyl
c. Hydroxyl
d. Carboxyl
10. Tailing of mercury is due to formation of
a. Mercuric
b. Mercurous
c. Mercuric chloride
d. Mercurous oxide
11. Equilibrium of the reaction: 2SO2.7 + O2 2SO3 + 45.2Kcal will shift to left at:
a. Low temperature and low pressure
b. High temperature and low pressure
c. Low temperature and high pressure
d. High temperature and high pressure
Group 'B'
Give short answer to the following answer (8x5=40)
1. How does Bohr's theory explain the origin of hydrogen spectra? Name the different spectral lines with labeled diagram. (2+3)
OR
a. What is mean by periodicity of element? (1)
b. What is meant by ionization energy and electronegativity? What are the factors affecting them? (3)
c. Second ionization energy of an element is always greater than its first ionization energy, why? (1)
2. (a) Give the balance chemical equation for the preparation for the preparation of ammonia from nitrogen and hydrogen. (1)
(b) What are the proper physical conditions for better yield of ammonia? (2)
(c) Write the action of ammonia on:
i) CuSO4 solution (1)
ii) CO2 gas (1)
3) 10.3 gm of pure NaCO3 if treated with 7.9gm of HCL to produce NaCl, H2O and CO2
a) Find the limiting agent (1)
b) Calculate the mole of unreacted reagent left over. (1)
c) What volume of CO2 gas is produced at NTP? (1)
d) Calculate mass of NaCl formed? (2)
OR
What is redox reaction? Differentiate oxidant and reductant. (1+1)
Balance the following redox reaction by oxidation number method or ion electron method.
C12H22O11 + HNO3 -----> NO2 + C2H2O4 + H2O (3)
4. Hydrogen Sulphide is used as an analytical reagent for detection of salt during salt analysis in lab.
a. Write the chemical equation for the preparation of H2S gas and discuss about the working principle of Kipp's apparatus (4)
b. Show that H2S is acidic in nature. (1)
5. What do you mean by concentration of ores? Briefly describe the following process:
a. Gravity separation process
b. Forth floatation process (1+2+2)
6. What is the composition of Lassaigne's extract if the organic compound contains nitrogen? What is it alkaline in nature? How is presence of nitrogen detected? (2+1+2)
7. Write short note on:
a. Ozonolysis
b. Markonikov's rule (2+3)
8. Chemical industries are considered most important for nation's development. What are the major environmental impacts of chemical industry? What would you suggest to control it? (4+1)
Group 'C'
Give long answer to the following questions. (3x8=24)
9. State and explain Graham's law of diffusion.
How long will it take 600ml of Hydrogen gas to diffuse through a porous partition, if 300ml of oxygen diffuse through it in 10 minute under identical conditions? (4+4)
10. Halogens are highly reactive elements. They have high electro negativity values & they are even strong oxidizing agents.
a) Write down any two reactions which shows the oxidizing nature of halogens. (2)
b) What happens when excess NH2 is treated with Chlorine? (1)
c) What happens when Chlorine is treated with:
i) Cold & dil. NaOH
ii) Hot & conc. NaOH (1+1)
d) Define bleaching. Differentiate between bleaching action of Cl2 & SO2. (1+2)
OR
a. Sulphuric acid is known as king of chemicals. The industrial use of this acid can be taken as indicator of the economic development of that country. Describe the manufacture of this acid by contact process (with flow sheet diagram). (4)
b. What are nitrogen fertilizers that are commonly used in Nepal? Also write the basic principle involved in the production of one of the nitrogen fertilizer. (1+3)
11. An aromatic compound (X) is obtained when sodium benzoate is heated with soda lime. X when react with Cl2 in presence of sunlight give BHC.
a) Write the chemical equation for above reaction. (2)
b) What are aromatic compounds? (1)
c) What is aromaticity? Use Huckle's rule to show aromatic compound. (2)
d) What is Friedel's -Crafts alkylation reaction. (2)
e) Write the use of benzene. (1)
The End
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