When naphthalene balls are kept inside cotton and woollen clothes in an almirah, the naphthalene balls disappear slowly. Is it a physical change or a chemical change.
When naphthalene balls are kept inside cotton and woollen clothes in an almirah, the naphthalene balls disappear slowly. Is it a physical change or a chemical change.
When naphthalene balls are kept inside cotton and woollen clothes in an almirah, the naphthalene balls disappear slowly because they undergo sublimation.
Sublimation: The process of conversion of a substance from the solid state into gaseous state on heating directly without converting into liquid state.
- Example: Camphor, Naphthalene, Anthracene etc.
As naphthalene balls only change from solid to gaseous state without any change in their chemical composition or chemical properties, it is a physical change.
Physical change: A physical change involves the formation of no new substance and there is no change in the chemical composition of the substance undergoing the change.
- It is a temporary change.
- It is a reversible change as most of the times, the substance can be brought back to its original state.
- Only physical properties like hardness, colour etc. are changed during a physical change.
Chemical change: A chemical change involves the formation of one or more new substances and there is a change in the chemical composition of the substance undergoing the change.
- It is a permanent change.
- It is an irreversible change mostly as the substance undergoing change can not be brought back to its original state.
- Physical as well as chemical properties of the substance change during a chemical change.
When naphthalene balls are kept inside cotton and woollen clothes in an almirah, the naphthalene balls disappear slowly because they undergo sublimation.
Sublimation: The process of conversion of a substance from the solid state into gaseous state on heating directly without converting into liquid state.
- Example: Camphor, Naphthalene, Anthracene etc.
As naphthalene balls only change from solid to gaseous state without any change in their chemical composition or chemical properties, it is a physical change.
Physical change: A physical change involves the formation of no new substance and there is no change in the chemical composition of the substance undergoing the change.
- It is a temporary change.
- It is a reversible change as most of the times, the substance can be brought back to its original state.
- Only physical properties like hardness, colour etc. are changed during a physical change.
Chemical change: A chemical change involves the formation of one or more new substances and there is a change in the chemical composition of the substance undergoing the change.
- It is a permanent change.
- It is an irreversible change mostly as the substance undergoing change can not be brought back to its original state.
- Physical as well as chemical properties of the substance change during a chemical change.
