Advertisements
Advertisements
प्रश्न
Give a reason for the following.
Granulated zinc is preferred to metallic zinc in the preparation of hydrogen using dilute acid.
Advertisements
उत्तर
Zinc granules are preferred rather than pure zinc as impurity copper present in it has a catalysing effect and speeds up the rate of the reaction.
APPEARS IN
संबंधित प्रश्न
Give reason for the following:
Purified and dried hydrogen is collected over mercury.
How did the name 'hydrogen' originate?
Hydrogen can be prepared with the help of cold water. Give a reaction of hydrogen with:
A divalent metal
Complete and balance the following reaction.
Fe + H2O →_____________ +___________
Select the correct options for the following statement:
A foul smelling gas formed when hydrogen reacts with a molten non-metal, is ___.
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.
A white substance which leaves an amphoteric oxide as a residue [whose colour varies in the heated and in the cold state] and evolves a gas which turns lime water milky.
Complete and balance the equation:
[General method]
Reactions of active metals - cold water
Potassium- K + H2O → ______+ ______ [g]
Complete and balance the equation:
[General method]
Reactions of active metals - cold water
Sodium - 2Na + 2H2O → ______+ _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals with steam
Aluminium - 2Al + 3H2O → ______+ _______ [g]
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.
