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प्रश्न
Give balanced equation for the following conversion:
Zinc to sodium zincate – using an alkali.
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उत्तर
Zinc to sodium zincate.
\[\ce{Zn + 2NaOH ->\underset{\text{Sodium Zincate}}{Na2ZnO2} + H2}\]
संबंधित प्रश्न
Indicate which of the following statement is true and which is false:
Nitric acid cannot be used to prepare hydrogen by its action on active metals.
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.
Name the following:
A metallic oxide which can be reduced into metal by hydrogen.
How would you show that hydrogen is a non-supporter of combustion?
FILL IN THE BLANK
Sodium liberates hydrogen when treated with cold .............
FILL IN THE BLANK
........................ zinc is preferred over pure zinc in the laboratory preparation of hydrogen.
TRUE \ FALSE
Lead reacts briskly with dilute hydrochloric acid to form hydrogen.
Why is granulated zinc preferred in the laboratory preparation of hydrogen?
Name the impurities present in hydrogen prepared in the laboratory.
How can these impurities be removed?
Under what conditions can hydrogen be made to combine with chlorine?
Name the products and write the equation for the reaction.
How would you show that hydrogen is lighter than air?
Starting from zinc how would you obtain hydrogen using a dilute acid.
[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.
In the laboratory preparation of hydrogen from zinc & dilute hydrocholoric acid – state a reason for the addition of traces of copper [II] sulphate to the reaction medium.
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.
Give balanced equation for the following conversion:
Acidified water to hydrogen – by electrolysis.
Give reason for the following:
Copper does not displace hydrogen from dilute hydrochloric acid, but zinc does.
Give reason for the following:
In the laboratory preparation of hydrogen from zinc and dilute hydrochloric acid – the zinc used granulated zinc.
Complete and balance the equation:
[Laboratory method]
By action of dilute acid on zinc
Zinc - Zn + 2HCl → _____ + _____ [g]
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
The lower end of the thistle funnel should dip below the level of the acid in the flask.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
Hydrogen is not collected over air.
Give a reason for the following.
Nitric acid in the dilute form is not used in the laboratory preparation of hydrogen from metals.
The diagram represent the preparation and collection of hydrogen by a standard laboratory method.
State what difference will be seen if pure zinc is added in the distillation flask ‘X’ instead of granulated zinc.
The diagram represent the preparation and collection of hydrogen by a standard laboratory method.
Name a solution which absorbs the impurity – `"H"_2"S"`
The diagram represent the preparation and collection of hydrogen by a standard laboratory method.
State, why hydrogen is collected after all the air in the apparatus, is allowed to escape.
