IX Practical Chemistry KBSE Experiment No. 8

To Prepare Oxygen gas using Hydrogen peroxide and study its properties (Three Physical

and three Chemical)

Viva Voce
Q.1. What is the formula of Hydrogen Peroxide?

Ans. The formula of Hydrogen Peroxide is H2O2.


Q.2. Is Hydrogen Peroxide an element or Compound?

Ans. Hydrogen Peroxide is a compound.


Q.3. How many elements are present in Hydrogen Peroxide?

Ans. Two elements.


Q.4. Write down the name of the elements present in Hydrogen Peroxide.

Ans. Hydrogen and Oxygen


Q.5. How many atoms of Hydrogen are present in Hydrogen Peroxide?

Ans. Two atoms of Hydrogen are present.


Q.6. How many atoms of Oxygen are present in Hydrogen Peroxide?

Ans. Two atoms of Oxygen are present in Hydrogen Peroxide.


Q.7. How do you make the apparatus air tight?

Ans. The apparatus is made air tight with the help of Plaster of Paris.


Q.8. What is the formula of Plaster of Paris.

Ans. The formula of Plaster of Paris is 2CaSO4.H2O.


Q.9. What is the formula of Manganese Dioxide?

Ans. The formula of Manganese Dioxide is MnO2.


Q.10. Which elements are present in Manganese Dioxide?

Ans. Manganese and Oxygen are present.


Q.11. How many atoms of Oxygen are present in Manganese Dioxide?

Ans. Two atoms of Oxygen are present in Manganese Dioxide.


Q.12. Write down the Chemical equation of Oxygen preparation reaction.

Ans. 2H2O2 + MnO2 ------- MnO2 + 2H2O + O2.


Q.13 Why do you add up MnO2 with Hydrogen Peroxide?

Ans. Manganese Dioxide is used in this reaction as Catalyst.


Q.14. Is Oxygen an element or Compound?

Ans. Oxygen is an element.


Q.15. What is Catalyst (Catalytic Agent)?

Ans. The substance which changes the rate of Chemical reaction without itself undergoing

permanent chemical change is called Catalyst.


Q.16. What is the function of Manganese Dioxide in the experiment?

Ans. The use of Manganese Dioxide increases the speed of Chemical reaction.


Q.17. What do you understand by Positive or Negative Catalyst?

Ans. Positive Catalyst The Catalyst which increases the rate of chemical reaction is

called Positve Catalyst.

Negative Catalyst The Catalyst which reduces the rate of reaction is called Negative

Catalyst.


Q.18. Give some examples of Negative Catalyst?

Ans. The addition of Acetanilide reduces the decomposition of Hydrogen Peroxide into water

and Oxygen.


Q.19. Give some example of Positive Catalyst?

Ans. Oxides of Iron, Potassium and Aluminium and Manganese are used as Positive Catalyst.


Q.20 By which method oxygen is collected?

Ans. Oxygen is collected by downward displacement of water.


Q.21. Can we collect Carbon Dioxide also by downward displacement of water?

Ans. No, Carbon Dioxide can not be collected by this method because it is highly soluble in

water.


Q.22. Is Oxygen heavier or lighter than air?

Ans. Oxygen is slightly heavier than air.


Q.23. Why is it advised to keep the lower end of thistle funnel dipped in the liquid?

Ans. The lower end of thistle funnel should remain dipped so that the gas may not escape

through the thistle funnel.


Q.24. What is the colour of the Gas?

Ans. It is colourless.


Q.25. What is the odour (smell) of the Gas?

Ans. It is odourless.


Q.26. Is it soluble in water?

Ans. It is slightly soluble in water.


Q.27. What happens when burning match stick is introduced into oxygen gas jar?

Ans. The match stick burns more readily.


Q.28. What do you conclude from the fact that the burning match stick burns more readily

in oxygen?

Ans. We conclude that oxygen is supporter of combustion.


Q.29. What happens when burning magnesium wire is introduced into gas jar?

Ans. Mangesium wire continues burning producing Magnesium Oxide.

2Mg(s) + O2(g) --2MgO(s)


Q.30. What happen if burning Sulphur powder is introduced into oxygen gas jar?

Ans. Sulphur continues burning producing Sulphur Dioxide

S(s) + O2(g) ---- SO2(g)


Q.31. What happens if burning sodium piece is introduced into gas jar?

Ans. Sodium continues burning producing Sodium Peroxide.

2Na(s) + O2(g) (Excess) -----> Na2O2


Q.32. What happens when a piece of burning Phosphorus is introduced into gas jar?

Ans. Phosphorus burns in oxygen forming phosphorus Pentaoxide.

4P(s) + 5 O2(g) -----> 2P2O5


Q.33. Give four uses of Oxygen?

Ans.

1. Oxygen is most essential for all living bodies, both animals and plants. Oxygen is used

in hospitals for artificial respiration.

2. It is used for converting Pig iron into steel in the blast furnance.

3. Acetyline is mixed with oxygen for producing a temperature as high as 3000oC which is

used for welding and cutting materials.

4. Liquid Oxygen is used as burning fuel in space.


Q.34. What is the name of binary compound formed with Oxygen?

Ans. The binary compound with oxygen is called Oxide.


Q.35. How many kinds of oxides are there?

Ans. There are four kinds of oxides

1. Normal Oxides

2. Peroxides

3. Superoxides

4. Suboxides.


Q.36. What are Peroxides?

Ans. Peroxides are binary compounds containing two oxygen atoms linked together.


Q.37. What happens when peroxides are treated with water?

Ans. Peroxides produce Hydrogen Peroxides when treated with water.

Na2O2 + 2H2O ------> 2NaOH + H2O2


Q.38. What is the name of that chemical process in which oxygen combines with other elements?

Ans. It is known as Oxidation.


Q.39. Does catalyst change the end of chemical reation?

Ans. No, Catalyst does not change at the end of Chemical reactions.


Q.40. What is Catalyst?

Ans. The process by virtue of which a catalyst, changes the rate of reaction is called Catalyst.


Q.41. What are Promoters?

Ans. The substances which enhance the activity of a catalyst are known as Promoters.


Q.42. What are Catalytic Poisons?

Ans. The substance which reduce or spoil the activity of a Catalyst are called Catalytic Poisons.


Q.43. What is Homogeneous Catalysis?

Ans. If the Catalyst, Reactants and Products all are in one phase, then such Catalyst is called Homogeneous Catalysis.


Q.44. What are the precautions in this experiment?

Ans. The following precautions should be taken in this experiment.

1. The round bottom flask should be air tight.

2. Round bottom flask should be heated gently by the tip of the flame.

3. The lower end of the thistle funnel should be immersed in the liquid.