Advertisements
Advertisements
प्रश्न
Give reason:
A candle brought near the mouth of a jar containing hydrogen gas starts burning but is extinguished when pushed inside the jar.
Advertisements
उत्तर
Hydrogen is combustible, but it does not support combustion. So, the candle burns in air or oxygen when brought near the mouth of a jar containing hydrogen but is extinguished when pushed inside the jar as the supply of oxygen is cut off.
APPEARS IN
संबंधित प्रश्न
Match the statements in Column A with those in Column B.
| Column A | Column B |
|
1. A metal which reacts with cold water to from hydrogen. |
1. Reduction |
| 2. A gas which is inflammable and non-supporter of combustion | 2. Hydrogenation |
|
3. A process in which vanspati ghee is prepared from vegitable oils |
3. oxidation |
|
4. The removal ofhydrogen or addition of oxygen |
4. sodium |
| 5. The addition of hydrogen or removal of oxygen | 5. Hydrogen |
MULTIPLE CHOICE QUESTIONS
Hydrogen burns in oxygen to form
- hydrogen sulphide
- nitrates
- water
- ammonia
For laboratory preparation of hydrogen, give the following:
fully-labeled diagram
Hydrogen may be prepared in the laboratory by the action of a metal on an acid.
How would you modify your apparatus to collect dry hydrogen? Which drying agent would you employ for this purpose?
Give reason for the following:
In the preparation of hydrogen by electrolysis of water – the distilled water used is acidified.
Select the correct options for the following statement:
The metal which reacts with steam liberating hydrogen & the reaction is reversible.
Complete and balance the equation:
[General method]
Reactions of active metals - cold water
Sodium - 2Na + 2H2O → ______+ _______ [g]
Account for the following fact:
Though lead is above hydrogen in the activity series, it does not react with dilute hydrochloric acid or dilutes sulphuric acid.
Account for the following fact:
Potassium and sodium are not used to react with dilute ‘hydrochloric acid or dilute sulphuric acid in the laboratory preparation of hydrogen.
State why hydrogen is not prepared in the laboratory by the action of sodium with cold water.
