IX Practical Chemistry KBSE Experiment No. 9

To Prepare Ammonia Gas and Study its properties.

Viva Voce
Q.1. What is the formula of Ammonia?

Ans. NH3.


Q.2. Wha is the formula of Ammonium Chloride?

Ans. NH4cl.


Q.3. What is the formula of Quick Lime?

Ans. CaO.


Q.4. What is the chemical name of Quick Lime?

Ans. Calcium Oxide.


Q.5. What do you mean Sal Ammoniac?

Ans. Ammounium Chloride is also known as Sal Ammoniac.


Q.6. What is the molecular weight of Ammonia (NH3)?

Ans. The molecular weigth of Ammonia is 17.


Q.7. How will you prepare Ammonia in Science Laboratory?

Ans. Ammonia is prepared in the Laboratory by heating a mixture of Ammonium Chloride and

powdered quick lime (CaO) or Slaked lime Ca(OH)2.


Q.8. Write down the chemical equation concerning the preparation of Ammonia?

Ans.

2NH4cl + CaO --------> 2 NH3 + CaCl2 + H2O

2NH4Cl + Ca(OH)2 ----> 2NH3 + CaCl2 + 2H2O


Q.9. What are the other compounds which are formed besides Ammonia during chemical action

of Ammonium Chloride with Quick Lime or Slaked Lime?

Ans. The other components which are formed besides Ammonia are Calcium Chloride.


Q.10. Which ratio Ammonium Chloride and Dry Slaked lime are taken.

Ans. NH4Cl = 1 Part, Slaken Lime = 2 Parts i.e. 1:2


Q.11. How is Ammonia collected?

Ans. Ammonia is collected by upward displacement of Gas.


Q.12. It is lighter or heavier than air?

Ans. It is lighter than air.


Q.13. Do you heat the mixture of Ammonium Chloride and Slaked Lime?

Ans. Yes, heating is required.


Q.14. Do you collect the gas over water?

Ans. No, it can not be collected over water because it is soluble in water.


Q.15. How will you know that the jar is full with the gas?

Ans. A rod dipped in Hydrochloric Acid when brought near its mouth gives white fumes of

Ammonium Chloride. A moist red litmus paper brought near the mouth will turn blue.


Q.16. Why is it essential to take perfectly dry gas jars for the collection of gas?

Ans. Ammonia is highly soluble in water.


Q.17. How will you keep the Gas Jars on the table afte they have been filled with the

gas?

Ans. The Jars will be kept in the inverted position because the gas is lighter than air so

in this case there is less chance for the leakage of the gas.


Q.18. What precautions are observed in this case?

Ans.

1. Gas Jars should be perfectly dry.

2. The Gas Jar is placed in inverted position with the help of a stand for collecting the

gas.

3. Gas is collected by downward displacement of air.

4. The Jars should be placed in inverted position after they have been filled with the Gas.


Q.19. Can you take quick lime for preparing the gas?

Ans. Yes, we can take quick lime also for preparing the gas.


Q.20. What is the colour of Ammonia?

Ans. It is colourless.


Q.21. What is the smell of Ammonia?

Ans. It has pungent smell.


Q.22. What is the taste of Ammonia?

Ans. It has bitter taste.


Q.23. It is soluble in water?

Ans. It is highly soluble in water.


Q.24. It is heavier than air?

Ans. No, it is lighter than air


Q.25. What is the action of Ammonia on Hydrochloric Acid?

Ans. Ammonium chloride is formed.


Q.26. Why does Ammonia give white fumes with conc.HCl.

Ans. Ammonia Gas and Hydrochloric Acid combine chemically to form Ammonium Chloride. But

Ammonium chloride is sublime substance so due to sublimation it directly changes into solid

from gaseous state. Due to this fact white fumes are visible.


Q.27. What is meant by "Downward Displacement of Air"?

Ans. When a gas is collected during preparation by keeping the jar in inverted position then

denser air is displaced downward. Therefore this is method is called "Downward Displacement

of Air".


Q.28. What is the action of Ammonia on Phenolphtalene?

Ans. Phenolphtalene solution become pink showing that Ammonia has basic character.


Q.29. How can Ammonia Gas be dried during experiment?

Ans. Ammonia Gas can be dried by passing it through a U-tube containly Quick lime.


Q.30. What is Nessler's Reagent?

Ans. Potassium Mercury Iodide is called NESSLER'S Reagent. It is a obtained by the following

chemical action.

Hgl2 + 2Kl --------> k2(Hgl4)


Q.31. Why do you collect Ammonia by downward displacement of gas?

Ans.Ammonia gas in lighter than air so it is collected by downward displacement of gas.


Q.32. State whether Ammonia is an element or a compound?

Ans. Ammonia is a compound of Nitrogen and Hydrogen.


Q.33. Is it a Basic or Acidic Gas?

Ans. It is a Basic Gas and turns red litmus blue.


Q.34. What is Chemical name of Nessler's Reagent?

Ans. The Chemical name of Nessler's Reagent is Potassium Mercuric Iodide and its formula is

K2(Hgl4)


Q.35. What substance is obtained when Ammonia is dissolved in water?

Ans. Ammonium Hydroxide is formed

NH3 + H2O ----- NH4OH


Q.36. What happens when Ammonia is treated with Copper SUlphate solution?

Ans. If Ammonia is treated with Copper sulphate solution then blue solution of complex Tetra

Amine Cupric Sulphate is formed

CuSo4 + 4 NH3 ------> Cu (NH)4 SO4 / Tetra Amine Cupric Sulphate


Q.37. What are some important uses of Ammonia?

Ans.

1. It is used in Ice making and Refrigeration.

2. It is used in making washing soda.

3. Ammonia solution (NH4OH) is used in laboratory as reagent.


Q.38. How Nessler's reagent is prepared?

Ans. Nessler's Reagent is prepared by adding excess of Potassium Iodide (Kl) solution into

the solution of Mercuric Chloride (HgCl2). Then Potassium Hydroxide is added to make the

Solution Alkaline.


Q.39. How will you identify Ammonia Gas?

Ans.

1. It possess a peculiar type of pungent smell and turns red litmus blue.

2. It gives white fumes with HCl.


Q.40. What is the difference between NH3 and NH4?

Ans. NH3 represents a molecule of Ammonia gas and NH4 stands for Ammonium Radical.


Q.41. What is the action of Ammonia on water?

Ans. Ammonia dissolves in water an forms Ammonium Chloride.

NH3 + H2O -------> NH4OH


Q.42. Why is it advised not to collect Ammonia in wet jar?

Ans. Ammonia is highly solube so it dissolves in the water of the wet jar and forms Ammonium

Hydroxide. Hence no gas is left in the jar.


Q.43. What is the nature of the gas?

Ans. It is basic in nature and turns moist red litmus blue.


Q.44. What are some of its physical properties which you observe during its preparation

and collection.

Ans. It is colourless with pungent smell and it is lighter than air and highly soluble in

water.


Q.45. Does it support combustion?

Ans. No, it does not support combustion.


Q.46. Does it burn in air?

Ans. No, it does not burn in air.


Q.47. What is the action of Turmeric paper on Ammonia?

Ans. Turmeric paper turns brown.


Q.48. Why does it turn turmeric paper brown?

Ans. It has property of base.


Q.49. What is Ionic Equation for the preparation of Ammonia?

Ans. (Ca++ + 2OH-) + 2(NH++4 + Cl-) -------> (Ca++ + 2Cl-) + 2H2O + 2NH3


Q.50. What does it show when the red litmus is turned blue by the action of Ammonia?

Ans. It shows that Ammonia has the property ofa base.


Q.51. What are the main tests of this gas?

Ans.

1. It has a pungent smell.

2. It turns red litmus blue.

3. It gives white fumes of Ammonium Chloride with HCl.


Q.52. What is the formula of Liquor Ammonia?

Ans. NH4OH.


Q.53. How will you demonstrate the solubility of Ammonia?

Ans. Its solubility is demonstrated by Fountain's Experiment.


Q.54. What do you understand by Liquor Ammonia?

Ans. Strogest solution of gas in water is called Liquor Ammonia and when the solution is

boiled Ammonia is give out.


Q.55. What is taste of Ammonia?

Ans. Alkaline or bitter taste.


Q.56. Does Ammonia support combustion?

Ans. No it does not support combustion.


Q.57. What do you understand by Spirit of Hartshorns?

Ans. Solution of Ammonia in water i.e. NH4OH is called Spirit of Hartshorns.


Q.58. What happens when a lighted candle is introduced in the gas jar full of Ammonia?

Ans. Candle gets extinguished which proves that Ammonia does not support combustion.


Q.59. How will you prepare Nessler's Reagent?

Ans. Potassium Iodide solution is added slowly in Mercuric Chloride solution till the red

precipitate formed dissolves in it and then add KOH solution till it is alkaline. It is then

Nessler's Reagent.


Q.60. What happen when Dry Ammonia is treated with Red Litmus paper?

Ans. No Reaction.


Q.61. What happen if you keep empty jar over Ammonia gas jar?

Ans. Gradually Ammonia gas diffuses into the upper Gas jar.