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.
Do you think the formation of rust from iron is a chemical change?
उत्तर
Yes, rusting is a chemical change since a new substance is formed.
APPEARS IN
संबंधित प्रश्न
Fill in the blank
A new substance is formed in a _______ change.
State four conditions necessary for chemical reactions to take place.
Name the type of chemical reaction shown by the following equation:
Fe + CuSO4 → FeSO4 + Cu
Give an example of the following chemical change.
Two solids combine to form a liquid
What is observed in performing the following :
| Hydrogen | Oxygen | Carbon dioxide | Chlorine | |
| Litmus test | ||||
| Apply a burning splint to the gas | ||||
| Colour of gas | colourless | colourless | colourless | greenish-yellow |
| Odour of gas |
Give examples of exothermic reactions i.e. heat evolved in each of the following:
(a) reaction between a solid and a liquid
(b) reaction between two gases
Give two examples of exothermic reactions seen in everyday life.
Name the following:
The products obtained during ‘photosynthesis’ – which is a chemical change.
State the following reaction represent oxidation or reduction.
\[\ce{H->H+}\]
Explain with the help of balanced equations, how precipitation reactions are used for identifying the positive radicals in three different salts, each having a different cation [positive ion].
Higher order Thinking question
Peeled and unpeeled banana does not look the same. Does that mean peeling banana is a chemical change?
