Question

Which of these is a chemical property? color, compressibility, heat of combustion, malleability

Answer 1

Answer: Heat of combustion

Explanation: Color is a physical property but however, color change can occur due to a chemical reaction. Example change in oxidation state of Fe(ii) to Fe(iii) from green to greenish brown.

2Fe²+ + 3O2 = 2Fe2O3

(Green) (Brown)

Compressibility is a physical property usually attributed to liquid, solid and gases. It is the change in volume or shape of matter and sometimes state of matter in gases.

Heat of combustion however is a chemical property because it is the heat change or given off as energy when an atom, molecule or compound is reacted with oxygen. Example when an organic substance undergoes combustion reaction with oxygen, it produces CO2, H2O and heat.

C6H12O6 + 6O2 = 6CO2 + 6H2O + Heat

(Oxidation reaction of glucose during respiration).

Malleability is a physical property because it is visible without altering the chemical composition of the material. For a material to be malleable, it means it can be hammered into thin sheet, rolled or capable of been flexible. Malleability is a unique physical property attributed to metals.

Answer 2

Chemical changes only happen when the object changes form. Color is a physical property because you're not changing the object that you have, compressibility is also a physical property because you still have the same substance before and sfter, malleability again is another physical. Heat of combustion is physical, when you burn things it changes the substance. :)