Preparation of Oxygen

Q.

Why does sulphur dioxide turns acidified potassium dichromate paper green

Q. Explain the laboratory preparation of oxygen with hydrogen peroxide (H_{​​​​​​2}​​​​​O_{​​​​2}) and manganese dioxide (MnO_{​​​​2}).

Q.

6. Describe a simple experiment to show that 1/5th of air is oxygen

Q.

Give tests for oxygen gas.

Q.

In Lavoisier's experiment what happened to the water of beaker?

1. Water level falls

2. Water level remains same

3. Water level starts getting colored

4. Water level rises

Q.

Which are the reasons of oxygenated water being preferred over potassium chlorate for preparation of oxygen?

1. Oxygenated water does not require heating

2. Rate of evolution of oxygen is under control

3. Oxygenated water is safer than potassium chlorate

4. All of these

Q. <!--td {border: 1px solid #cccccc;}br {mso-data-placement:same-cell;}--> How is oxygen prepared from potassium chlorate?

Q.

Water rises in the beaker during Lavoisier’s experiment due to which phenomenon?

1. Air gets released by mercury

2. Oxygen is used by mercury

3. Air gets absorbed in water

4. None

Q.

In Lavoisier's experiment which element is taken in retort and heated?

1. Liquid Nitrogen

2. Lead

3. Tin

4. Mercury

Q. Electrolysis of water gives dioxygen gas - True or False?

1. True
2. False

Q. Which of the following process releases oxygen into the air?

1. Photosynthesis
2. Respiration
3. Transpiration
4. Digestion

Q.

Explain with equations how sulphur dioxide(SO₂) is prepared in the laboratory.

Q. An oxidation reaction involves addition of

(a) oxygen only
(b) hydrogen only
(c) oxygen or removal of hydrogen
(d) hydrogen or removal of oxygen

Q. The observation seen in the bell-jar while experimenting for components of air is:

1. brown fumes are seen initially in the bell-jar and the level of water rises up
2. black fumes are seen initially in the bell-jar and the level of water rises up
3. brown fumes are seen initially in the bell-jar and the level of water falls down
4. black fumes are seen initially in the bell-jar and the level of water falls down

Q. What happens when following are heated?
Potassium nitrate