Classify the following as physical or chemical change. Think of a reason in your mind.

Burning of phosphorous

Classify the following as physical or chemical change. Think of a reason in your mind.

Classify the following as physical or chemical change. Think of a reason in your mind.

Setting of cement

Classify the following as physical or chemical change. Think of a reason in your mind.

Breathing by humans

Classify the following as physical or chemical change. Think of a reason in your mind.

Respiration by cows

Classify the following as physical or chemical change. Think of a reason in your mind.

Heating of ammonium chloride 

Classify the following as physical or chemical change. Think of a reason in your mind.

Conversion of sulphur dioxide to sulphur trioxide

Classify the shown pictures into physical and chemical changes:

$2{\mathrm{KClO}}_3\stackrel{{\mathrm{MnO}}_2}{\to }2\mathrm{KCl}+3{\mathrm{O}}_2$

The given reaction is: