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?
उत्तर
No rusting is a chemical change and cannot be reversed.
APPEARS IN
संबंधित प्रश्न
Give one example that illustrates the following characteristics of a chemical reaction:
Change in state
What do you observe when Iron nail is kept in copper sulphate solution for sometime.
What are oxides ?
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
The white particles of baking soda disappear when put in lemon juice. This means that it is a ______ change.
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
Oxygen is a ______ in respiration.
State the main characteristics of chemical reactions. Give at least one example in each case.
Give a chemical test to distinguish between the following gases.
NH3 and SO2
Give reason for the following:
The catalytic oxidation of sulphur dioxide to sulphur trioxide is represented by a double arrow {⇌}
between the reactants and products, formed in the chemical reaction.
Complete the table given below.
| Heat on Zinc nitrate | Colour of residue |
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
