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प्रश्न
Give reason for the following:
Dilute sulphuric acid cannot be replaced by concentrated acid in the preparation of hydrogen.
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उत्तर
Dilute sulphuric acid cannot be replaced by concentrated acid in the preparation of hydrogen because it is a strong oxidising agent and it will produce sulphur dioxide.
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संबंधित प्रश्न
Fill in the blank
Hydrogen reacts with metal oxides to form ............and....................
Give reason for the following:
Though hydrogen is lighter than air it cannot be collected by downward displacement of air.
MATCH THE COLUMNS
| column A | column B |
| 1. `""2H_2 + O_2 → 2H_2O` | A. This reaction is not possible |
| 2. `""H_2+CI_2 →2HCI` | B.This reaction is exothermic to the extent of explosion |
| 3.`""ZaO+ H^2→Zn +H_2O` | C.This reaction is known as Haber process |
| 4.`""Cu + H_2SO^4 → CuSO_4 + H_2 ` | D.This reaction illustrates the reducing property of bydrogen |
| 5.`""N_2 +3H_2 → 2NH_3 +heat ` | E. This reaction takes place in diffused sunlight |
| F. This reaction is a method of preparation of hydrogen |
For laboratory preparation of hydrogen, give the following:
materials used
Where does hydrogen occur in a free state?
Why are the following metals not used in the lab. preparation of hydrogen?
aluminium
Complete and balance the equation:
[General method]
Reactions of active metals - cold water
Calcium - Ca + H2O → ______+ _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals - alkali [conc. soln.]
Aluminium - 2Al + 2NaOH + 2H2O → ______ + _______ [g]
2Al + 2KOH + 2H2O → _____ + _____ [g]
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.
Select the correct answer to the reactant added, to give the product in the preparation of hydrogen gas.
\[\ce{Fe3O4 + H2}\]
