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प्रश्न
Account for the following fact:
Though lead is above hydrogen in the activity series, it does not react with dilute hydrochloric acid or dilutes sulphuric acid.
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उत्तर
Pb (lead) is above hydrogen in reactivity series. With dil. HCl, Pb forms PbCl2 and with dil. H2SO4, Pb forms PbSO4 both PbCl2 and PbSO4 are insoluble and forms a respective coating to stop the further reaction.
संबंधित प्रश्न
Hydrogen is ______ than air.
TRUE \ FALSE
reacts with hot water to form copper oxide and hydrogen.
What is noticed if the products are not allowed to escape?
Give reason for the following:
Dilute sulphuric acid cannot be replaced by concentrated acid in the preparation of hydrogen.
Hydrogen may be prepared in the laboratory by the action of a metal on an acid.
Which of the acids dilute sulphuric, concentrated sulphuric, dilute nitric acid and concentrated nitric acid would you choose? Explain why you would not use the acids you reject.
Complete and balance the following reaction.
Zn + HCl →_____________ +___________
Select the correct options for the following statement:
The metal used as a catalyst in hydrogenation of oils.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
An efflorescent substance which leaves a residue having the same colour as the substance and evolves a gas which changes the colour of cobalt chloride paper.
Complete and balance the equation:
[General method]
Reactions of metals with steam
Zinc - Zn + H2O → ______+ _______ [g]
Give a balanced equation for the following conversion.
\[\ce{NH3<-H2->H2S}\]
