Question

State why hydrogen is not prepared in the laboratory by the action of- a)sodium with cold water b)calcium with dilute sulphuric acid c)lead with dilute hydrochloric acid
Plzz help

Answer 1

Reaction with sodium is explosive/ highly exothermic in nature
Calcium is expensive
Reaction with lead will make an insoluble coating which will prevent further reaction

Answer 2

The Hydrogen will not be prepared usually in the laboratories due to its reaction with:

• a) The Sodium and cold water reacts to give hydrogen it is very vigorously and even leads to the explosion while carrying this process out.

        Sodium + Water = Sodium Hydroxide + Hydrogen

• b) The Calcium and dilute sulphuric acid to produce Hydrogen will leads to be very expensive which cannot take place without the perfect catalysts and other requirements which are of very high cost.

       calcium + dilute sulphuric acid = calcium sulfate + hydrogen

• c) When Lead with dilute hydrochloric acid are reacted, the reaction will not be proceeded to further step which will lead to no production of the Hydrogen as there will be an insoluble coating of the Lead which will stop the reaction there itself.

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