Advertisements
Advertisements
प्रश्न
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Can you change rust back into iron by some simple method?
Advertisements
उत्तर
No, rusting is a chemical change and cannot be reversed.
APPEARS IN
संबंधित प्रश्न
FILL IN THE BLANK
Negatively charged ions are called ..........
What are homogenous reactions ?
Write true or false :
When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet .
Name the type of chemical reaction shown by the following equation:
2Mg + O2 → 2MgO
Give an example of a reaction where the following are involved
Electricity
Give reason for the following:
Blue solution of copper sulphate changes to green when a piece of iron is added to this solution.
Select the correct answer for the following options:
The gas obtained when potassium chlorate is heated in the presence of a catalyst.
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 solid which evolves two colourless gases which on cooling combine and condense on the cooler parts of the test tube.
State whether the following reaction is oxidation or reduction.
\[\ce{Na->Na+}\]
Write five changes in the characteristics of a substance that can take place during a chemical change.
