Advertisements
Advertisements
Question
Give four difference between physical and chemical changes.
Advertisements
Solution
The differences are Physical and Chemical Changes:
Physical change
- In a physical change no new substance is formed and the chemical composition of substance remains same. There are changes only in physical properties and state.
- Temporaiy change which can be reversed by simple physical methods.
- Weight of original substance doesn’t change
- Energy like heat, light etc. may or may not be absorbed or released
Chemical change
- In a chemical change new substance with entirely different chemical composition and properties is formed.
- Permanent change and irreversible
- Weight of original substances may increase or decrease
- Energy like heat, light etc. are given out or absorbed.
APPEARS IN
RELATED QUESTIONS
Which of the following are chemical changes?
- Growth of a plant
- Rusting of iron
- Mixing of iron fillings and sand
- Cooking of food
- Digestion of food
- Freezing of water
- Burning of candle
Tick the most appropriate answer.
4. Chemical changes involve
- change in shape.
- change in size.
- change in molecular composition.
- none of these
State whether the following is physical or chemical changes.
mixing oil with water —
Write true or false
Burning of paper and formation of curd are reversible changes.
Given reason:
Freezing of water to ice and evaporation of water are physical changes.
Change is the law of nature which occurs in everyday life.
State when a substance [i.e. matter] undergoes a kind of change.
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.
______ is the substance that is dissolved in a solvent.
Give two examples for the following case:
Physical changes which are not reversible
