NEB Class 11 Chemistry Model Set 1 | NepaliEducate

Instructions: Candidates are required to give their answers in their own words as far as practicable. The figures allocated in the margin indicate full marks.

Group 'A'

Circle the best alternative of the following questions:(1 * 11 = 11)

1. Which of the following laws give volume-temperature relationship?
   1. Charle's law
   2. Grahm's law
   3. Boyle's law
   4. Dalton's law
2. Which one of the following is fixed cost?
   1. Depreciation
   2. Electricity
   3. Raw material
   4. Transportation
3. Which one of the following is radioactive hydrogen?
   1. Protium
   2. Deuterium
   3. Tritium
   4. Molecular hydrogen
4. Which property of liquid is related to capillary action?
   1. Surface tension
   2. Viscosity
   3. Evaporation
   4. Vaporization
5. 20g of 20% pure CaCO₂ can produce
   1. 0.896 L CO₂ at NTP
   2. 0.986 L CO₂ at NTP
   3. 0.869 L CO₂ at NTP
   4. 0.0896 L CO₂ at NTP
6. Hybridization of B in BF₃ is
   1. sp
   2. sp²
   3. sp³
   4. sp²d
7. Sodium-glucose pump is
   1. Secondary passive pump
   2. Primary passive pump
   3. Primary active pump
   4. Secondary active pump
8. How co-ordinate covalent bond is formed?
   1. By mutual sharing of electrons
   2. Transfer of electrons
   3. Sharing electrons are donated by a single atom.
   4. Attraction between kernel and mobile electrons
9. If pressure is increased, reaction will shift 2NO + O₂ ⇌ 2N₂O₂(g)
   1. Backward direction
   2. Forward direction
   3. Neither forward nor backward direction
   4. Pressure does not affect
10. Which of the following is called a scrubber?
    1. Electrostatic precipitator
    2. Arsenic purifier
    3. Washing tower
    4. Drying tower
11. Which one of the following is a drawback of Bohr's atomic model?
    1. Atomic stability
    2. Radius of n deg orbit
    3. Energy of n ^ mathfrak m orbit
    4. Zeeman effect

Group 'B'

Give short answers to the following questions

1. Rate of reaction depends up on concentration of reactants.
   1. State the law of mass action.
   2. Prove that K₀ = K_e

   Or

   A hydrogen spectrum is one of the important findings out of Bohr's atomic model which inaugurated the new concept of spectra.
   1. How hydrogen spectra are produced?
   2. Draw a neat and labeled diagram of the hydrogen spectra.
   3. Define the series which belongs to the visible region.
2. Redox reaction goes on hand to hand. One example of a redox reaction is given below
   KMnO₄ + H₂SO₄ + CO -> K₂SO₄ + MnSO₄ + H₂O + CO₂
   
   1. Balance the above reaction either by oxidation number or ion-electron method.
   2. Identify reducing and oxidizing agents in the reaction.
   3. Find the oxidation number of P in H₃PO₄ and H₃PO₃ (1)
3. Given reaction is taken from the contact tower of the contact process for the manufacture of H₂SO₄ before equilibrium is set up.

   2SO₂ + O₂ -> 2SO₃

   If 10 g of SO₂ reacts with 2 g of O₂ in the reaction,

   1. Find out the limiting reagent.
   2. Find out the mass of SO₃ formed.
   3. Prove that molecular mass 2 x vapor density.
4. H₂S gas is one of the frequently used analytical reagents in salt analysis. How it can be used for the detection of II group basic radicals? Give two reactions to show its reducing property. What happen when H₂S gas is passed into acidified KMnO₄, solution?

   Or

   Charcoal is one of the allotropes of carbon which is applied for purification of various organic compounds during research of new compound.
   1. What is activated charcoal?
   2. Define allotropy
   3. Name the recently discovered allotrope of carbon and give its two applications.
   4. Graphite is good conductor. Why?
5. Ores are the buried money for underdeveloped countries like Nepal. However, metallurgical operations are not being sufficiently adopted in our country yet.
   1. Define ore.
   2. What is roasting?
   3. What are flux and gangue?
   4. Give one ore of aluminium.
6. Define isomerism. Write all possible isomers of C₄H₁₀ with their IUPAC name. What are the functional group of aldehyde and ester? Give one compound of each.
7. Identify compound A with suitable reaction.
   1. What is homologous series?Write its three characteristic features.
   2. What is gasoline additive? Give one example.
8. Ammonia is manufactured by Haber's process from the mixture of N₂ and H₂ in ratio 1:3 by volume.
   1. Write principle reaction and draw flow sheet diagram.
   2. What reaction occurs in purifying tower?
   3. What happen when excess NH₃ is treated with Cl₂ gas?

Group C

Give long answer to the following questions
9. Define Boyle's law. Derive combine gas equation. At what conditions real gas behaves as ideal gas? A drop of oil having 2 ml volume floating on the water surface at 2 atm pressure and 200K temperature is forcedly emerged into water at the depth where pressure is 4 atm and temperature is 200K. Find out volume of oil drop at the depth.

   Or

   Bohr's atomic theory is based up on plank's quantum theory.
   1. Write the main postulate of Bohr's atomic theory.
   2. Give three merits and demerits of this theory.
   3. State Heisenberg's uncertainty principle.
10. What is oxide? Classify the following oxides.
    1. Al₂O₃
    2. SO₂
    1. Write the action of Zn with (i) Hot and conc. HNO, and (ii) very dilute HNO,. Mention the hazardous effects of NH₃.
    2. What is nascent hydrogen? What happen when a small piece of zinc metal is added in to acidified KMnO solution?
    3. Mention two harmful effects and two control measures of ozone layer depletion
11. What is foreign element? How Cl is detected as foreign element (reaction only)?
    1. Write one example reaction of each
       1. Wurtz reaction and
       2. Friedelcraft's alkylation
    2. Give two tests to distinguish ethene and ethyne.
    3. Define Huckel's rule and apply it to show benzene is an aromatic hydrocarbon. What is gasoline? The octane number of gasoline is 80. What does it mean?