ICSE Class 10

General instructions: Answer all questions. Marks are shown in brackets [ ].

Objective

1. 1.
   (ii) Ammonia dissolves in Water to give

   1. A. Ammonium hydroxide
   2. B. Ammonium oxide
   3. C. Ammonium chloride
   4. D. none of these
   [1]
2. 2.
   A basic gas extremely soluble in water:

   1. A. Ammonia (NH₃)
   2. B. Helium (He)
   3. C. Hydrogen Sulfide (H₂S)
   4. D. Hydrogen (H₂)
   [1]
3. 3.
   Heating ammonium chloride with sodium hydroxide produces _______.

   1. A. ammonia
   2. B. nitrogen
   [1]
4. 4.
   Which experiment demonstrates the extreme solubility of ammonia in water?

   1. A. Electrolysis of water
   2. B. Fountain experiment
   3. C. Thermit reaction
   4. D. Displacement reaction
   [1]
5. 5.
   Complete the table by identifying the name of the process that produces ammonia as its output.

   Name of process	Inputs	Equations	Output
   			Ammonia

   1. A. Contact Process
   2. B. Haber Process
   3. C. Ostwald Process
   4. D. Solvay Process
   [1]
6. 6.
   Nitrogen gas can be obtained by heating

   1. A. ammonium nitrate
   2. B. ammonium nitrite
   3. C. magnesium nitride
   4. D. ammonium chloride
   [1]
7. 7.
   Which of the following correctly represents the reaction between lead nitrate and ammonium hydroxide?

   1. A. Pb(NO₃)₂ + NH₄OH → Pb(OH)₂ + NH₄NO₃
   2. B. Pb(NO₃)₂ + 2NH₄OH → Pb(OH)₂ + 2NH₄NO₃
   3. C. Pb(NO₃)₂ + NH₄OH → PbO + NH₄NO₃ + H₂O
   4. D. 2Pb(NO₃)₂ + NH₄OH → Pb₂(OH)₂ + NH₄NO₃
   [1]
8. 8.
   Which of the following represents the balanced chemical equation for the reaction when magnesium nitride is warmed with water?

   1. A. Mg₃N₂ + 3H₂O → 3MgO + 2NH₃
   2. B. Mg₃N₂ + 6H₂O → 3Mg(OH)₂ + 2NH₃
   3. C. Mg₃N₂ + 2H₂O → 3Mg + 2NH₃ + O₂
   4. D. Mg₃N₂ + H₂O → Mg(OH)₂ + NH₃
   [1]
9. 9.
   What do you observe and which of the following represents the balanced chemical equation when ammonia burns in pure oxygen?

   1. A. Observation: Greenish-yellow flame; Equation: 4NH₃ + 3O₂ → 2N₂ + 6H₂O
   2. B. Observation: Blue flame; Equation: NH₃ + O₂ → N₂ + H₂O (unbalanced)
   3. C. Observation: Bright white flame; Equation: 2NH₃ + O₂ → N₂ + 3H₂O
   4. D. Observation: Reddish-brown flame; Equation: 4NH₃ + 5O₂ → 4NO + 6H₂O
   [1]
10. 10.
    Name the gas produced when excess ammonia reacts with chlorine.

    1. A. Hydrogen chloride
    2. B. Nitrogen
    3. C. Chlorine dioxide
    4. D. Ammonium gas
    [1]
11. 11.
    On passing ammonia gas over heated copper oxide for some time, a reddish-brown residue is left behind. What property of ammonia is demonstrated here?

    1. a. Basic property
    2. b. Oxidising property
    3. c. Reducing property
    4. d. Acidic property
    [1]
12. 12.
    When ammonium hydroxide is added to solution B, a pale blue precipitate is formed. This pale blue precipitate dissolves in excess ammonium hydroxide giving an inky blue solution. Which cation is present in solution B, and what is the probable colour of solution B?

    1. A. Cation: Cu²⁺; Colour: Blue
    2. B. Cation: Fe²⁺; Colour: Green
    3. C. Cation: Zn²⁺; Colour: Colourless
    4. D. Cation: Al³⁺; Colour: White
    [1]
13. 13.
    Which of the following correctly describes the physical and chemical properties of nitrogen?

    1. A. Nitrogen is a colorless, odorless gas that is highly soluble in water and supports combustion.
    2. B. Nitrogen is a colorless, odorless, and tasteless gas that is chemically inert at ordinary temperatures due to its triple covalent bond and does not support combustion.
    3. C. Nitrogen is a reactive gas with a pungent odor, turns litmus red, and readily dissolves in water.
    4. D. Nitrogen is a yellowish gas that is highly combustible and reacts vigorously with all metals at room temperature.
    [1]
14. 14.
    Identify the substance **Q** based on the following information: The white crystalline solid **Q** is soluble in water. It liberates a pungent smelling gas when heated with sodium hydroxide solution.

    1. A. Ammonium chloride
    2. B. Sodium chloride
    3. C. Calcium carbonate
    4. D. Potassium nitrate
    [1]
15. 15.
    A substance 'A' was heated with slaked lime and a gas 'B' with a pungent smell was obtained. Which of the following correctly identifies substances A and B along with the balanced equation for the reaction?

    1. A. A is ammonium chloride (NH₄Cl), B is ammonia (NH₃); 2NH₄Cl + Ca(OH)₂ → CaCl₂ + 2NH₃ + 2H₂O
    2. B. A is sodium chloride (NaCl), B is chlorine (Cl₂); 2NaCl + Ca(OH)₂ → CaCl₂ + 2NaOH + Cl₂
    3. C. A is ammonium sulfate ((NH₄)₂SO₄), B is sulfur dioxide (SO₂); (NH₄)₂SO₄ + Ca(OH)₂ → CaSO₄ + 2NH₃ + 2H₂O
    4. D. A is calcium carbonate (CaCO₃), B is carbon dioxide (CO₂); CaCO₃ + Ca(OH)₂ → 2CaO + 2CO₂ + H₂O
    [1]
16. 16.
    Which of the following is the correct balanced chemical equation for the reaction of ammonia with oxygen in the presence of a platinum catalyst?

    1. A. NH₃ + O₂ → NO + H₂O
    2. B. 4NH₃ + 5O₂ → 4NO↑ + 6H₂O
    3. C. 4NH₃ + O₂ → 4NO↑ + 6H₂O
    4. D. 2NH₃ + 3O₂ → 2NO↑ + 3H₂O
    [1]
17. 17.
    Ammonia solution in water gives a blue precipitate when it combines with a solution of copper salt. The blue precipitate further dissolves in excess of ammonia solution to give an azure blue solution. Which of the following correctly explains the formation and dissolution of the blue precipitate with equations?

    1. A. Ammonia reacts with copper sulphate to form copper hydroxide precipitate, which dissolves in excess ammonia to form tetraamminecopper(II) sulphate.
    2. B. Ammonia reacts with copper sulphate to form copper oxide precipitate, which dissolves in excess ammonia to form copper nitrate.
    3. C. Ammonia reacts with copper sulphate to form copper carbonate precipitate, which remains insoluble in excess ammonia.
    4. D. Ammonia reacts with copper sulphate to form copper hydroxide precipitate, which decomposes into copper oxide and water in excess ammonia.
    [1]
18. 18.
    Why is the optimum temperature for the Haber's process 450-500 °C, even though the reaction is exothermic and lower temperatures would favour the formation of ammonia?

    1. A. Lower temperatures slow the reaction rate too much, making the process inefficient despite higher yield.
    2. B. Higher temperatures are required to shift the equilibrium toward ammonia formation.
    3. C. The reaction becomes endothermic at temperatures below 450 °C, reducing ammonia production.
    4. D. Catalysts used in the process only function effectively at temperatures above 500 °C.
    [1]
19. 19.
    Which of the following nitrates, when heated, decomposes completely leaving no solid residue behind?

    1. A. Sodium nitrate (NaNO₃)
    2. B. Ammonium nitrate (NH₄NO₃)
    3. C. Potassium nitrate (KNO₃)
    4. D. Lead nitrate (Pb(NO₃)₂)
    [1]
20. 20.
    Complete and balance the following chemical equation: $\mathrm{NH_3} + \mathrm{P_2O_5} + \mathrm{H_2O} \rightarrow$

    1. A. $6 \mathrm{NH_3} + \mathrm{P_2O_5} + 3 \mathrm{H_2O} \rightarrow 2 (\mathrm{NH_4})_3\mathrm{PO_4}$
    2. B. $2 \mathrm{NH_3} + \mathrm{P_2O_5} + \mathrm{H_2O} \rightarrow 2 \mathrm{NH_4PO_3}$
    3. C. $4 \mathrm{NH_3} + \mathrm{P_2O_5} + 2 \mathrm{H_2O} \rightarrow 2 (\mathrm{NH_4})_2\mathrm{HPO_4}$
    4. D. $\mathrm{NH_3} + \mathrm{P_2O_5} + \mathrm{H_2O} \rightarrow \mathrm{NH_4H_2PO_4} + \mathrm{HPO_3}$
    [1]