Advertisements
Advertisements
प्रश्न
In the laboratory preparation of hydrogen from zinc & dilute hydrocholoric acid – state a reason for the collecting the hydrogen by downward displacement of water and not air & collecting it after all the air in the apparatus is allowed to escape.
Advertisements
उत्तर
Hydrogen is collected by downward displacement of water as it is slightly soluble in water and in air it form explosive mixture with air and also hydrogen is lighter than air.
APPEARS IN
संबंधित प्रश्न
Indicate which of the following statement is true and which is false:
Zinc can liberate hydrogen from water, acid and alkali solution.
Give reason for the following:
Nitric acid not used for the preparation of hydrogen gas?
Name the following:
A metal which liberates hydrogen only when steam is passed over red hot metal.
Draw a neat and well-labelled diagram for the laboratory preparation of hydrogen.
How is hydrogen gas collected? Why?
FILL IN THE BLANK
........................ zinc is preferred over pure zinc in the laboratory preparation of hydrogen.
Under what conditions can hydrogen be made to combine with chlorine?
Name the products and write the equation for the reaction.
Give reason:
Apparatus for laboratory preparation of hydrogen should be airtight and away from a naked flame.
Starting from zinc how would you obtain hydrogen using an alkali.
[Give balanced equation & name the product formed in the case other than hydrogen].
Name a metal which will not react with the reactants above to give hydrogen.
Draw neat labelled diagrams for two different experiments to prove that – hydrogen is lighter than air.
Give reason for the following:
Copper does not displace hydrogen from dilute hydrochloric acid, but zinc does.
Complete and balance the equation:
[Laboratory method]
By action of dilute acid on zinc
Zinc - Zn + 2HCl → _____ + _____ [g]
Give a balanced equation for the following conversions sodium plumbite from lead.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
The complete apparatus is air-tight.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
Dilute nitric acid is not preferred as the reactant acid.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
Hydrogen is not collected over air.
Name the following.
A gaseous reducing agent which is basic in nature.
The diagram represent the preparation and collection of hydrogen by a standard
laboratory method.
State what is added through the thistle funnel ‘Y’
