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प्रश्न
Give a reason for the following.
Hydrogen is collected by the downward displacement of water and not of air, even though it is lighter than air.
उत्तर
Hydrogen is collected by the downward displacement of air because of
- It is insoluble in water.
- It forms an explosive mixture with air.
संबंधित प्रश्न
From the knowledge of activity series, name a metal which shows the following properties:
It displaces hydrogen from dilute HCl.
From the knowledge of activity series, name a metal which shows the following properties:
It forms a base which is insoluble in water.
Hydrogen can be prepared with the metal zinc by using:
acid
Give an equation.
A small piece of calcium metal is put into a small trough containing water. There is effervescence and white turbidity is formed.
What do you observe when a few drops of red litmus solution are added to the turbid solution.
Which metal is preferred for collecting hydrogen from:
Write the balanced equation
Hot water
Write a balanced equation for the reaction named metal with (i) boiling water (ii) steam.
When hydrogen is passed over a black solid compound A, the products are a 'colorless liquid' and a 'reddish-brown metal B'.
Substance B is divided into two parts each placed in separate test tubes.
Dilute HCl is added to one part of substance B and dilute HNO3 to the other.
- Name the substances A and B.
- Give two tests for the colourless liquid formed in the experiment.
- What happens to substance A when it reacts with hydrogen? Give reasons for your answer.
- Write an equation for the reaction between hydrogen and substance A.
- Is there any reaction between substance B and dilute hydrochloric acid? Give reasons for your answer.
Helium is preferred to hydrogen for filling balloons because it is:
State why hydrogen is not prepared in the laboratory by the action of lead with dilute hydrochloric acid.
Name the following.
The salt formed when aluminium reacts with potassium hydroxide, during the preparation of hydrogen from alkalis.
