Advertisements
Advertisements
Question
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.
Advertisements
Solution
Otherwise gas produced will escape through thistle funnel.
RELATED QUESTIONS
Indicate which of the following statement is true and which is false:
Zinc can liberate hydrogen from water, acid and alkali solution.
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.
Name the chemicals required to prepare hydrogen gas in the laboratory.
How would you show that hydrogen is a non-supporter of combustion?
Multiple Choice Question
In metal activity series the more reactive metals are at
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.
Why is granulated zinc preferred in the laboratory preparation of hydrogen?
Give a test to identify hydrogen ?
Name the impurities present in hydrogen prepared in the laboratory.
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.
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.
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.
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.
Draw neat labelled diagrams for two different experiments to prove that – hydrogen is lighter than air.
Give balanced equation for the following conversion:
Zinc to sodium zincate – using an alkali.
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]
Give a balanced equation for the following conversions sodium aluminate from aluminium.
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.
Give a reason for the following.
Nitric acid in the dilute form is not used in the laboratory preparation of hydrogen from metals.
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’
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.
