Advertisements
Advertisements
Question
Define a chemical change. Give two examples of the above changes.
Advertisements
Solution
A permanent change in which new substances are formed whose composition and properties are completely different from those of the original
substances.
Chemical change:
(i) Burning of wood.
(ii) Breathing.
RELATED QUESTIONS
Classify the following as chemical or physical change:
Burning of paper and wood
Explain why burning of wood and cutting it into small piece are considered as two different types of changes.
Write true or false for the statement.
Dissolving of solute in a solvent and rusting of iron are both physical changes.
State the differences between a physical change and a chemical change.
Classify the following changes as physical or chemical:-boiling
Fill in the blank.
Growing of a seedling into a plant is _______ change.
True or false
Change of seasons is a non-periodic change.
True or false
Dissolving of a solid in liquid is a physical change.
Sublimation is classified as a physical change. Why ?
State the various conditions that favour the process of evaporation.
Classify the following as physical or chemical change :
Condensation of steam
What is a chemical change ? Give two examples of chemical changes.
Classify the following as a physical or a chemical change.
Drying of wet clothes
Match the examples of changes in List I with the correct.
| List I | List II |
| 1. Expansion of a steel rod on heating | A: Physical change |
| 2. Rotting of eggs | B: Chemical change |
| 3. Milk turning sour | |
| 4. Tarnishing of copper | |
| 5. Separation of naphthalene from a mixture of naphthalene and sodium chloride. |
Give a reason why – Heating a platinum wire is a reversible change but, heating a magnesium wire is an irreversible change.
Give a reason why rusting of iron is a chemical change but, the magnetization of iron is a physical change.
Physical Change: Boiling::Chemical Change: ______.
Give two examples for the following case:
Physical changes which are reversible
Give two examples for the following case:
Physical changes which are not reversible
