A physical change is exemplified by the
A physical change is exemplified by the
- A) burning of bush
- B) rusting of a metal
- C) dissolution of calcium in water
- D) heating of ammonium chloride
Correct Answer: D) heating of ammonium chloride
Explanation
This Chemistry question is asking about physical changes and which option is an example of such a change. Physical changes are changes that do not affect the chemical composition of a substance but change its physical properties such as shape, size, and state of matter.Option A, burning of bush, is an example of a chemical change because it involves a chemical reaction that changes the composition of the material being burned. Option B, rusting of a metal, is also a chemical change because it involves the reaction of metal with oxygen in the air to form a new compound.
Option C, dissolution of calcium in water, is a physical change because it involves the breaking of bonds between calcium ions and the anions they were originally bonded to. The calcium ions remain the same, they are just separated from their original compounds and dispersed in the water.
Option D, heating of ammonium chloride, is a physical change because it involves the application of heat to ammonium chloride, causing it to change from a solid to a gas without changing its chemical composition. This change is reversible, as if the gas is cooled it will return to its solid state.
Therefore, the correct answer to this question is option D, heating of ammonium chloride. This is because it is an example of a physical change, which does not change the chemical composition of the substance.