Answer
a) physical
b) physical
c) chemical
d) physical
Work Step by Step
a. The boiling point refers to a physical change of state
b. The temperature at which dry ice sublimes refers to a physical change of state
c. The flammability of ethyl alcohol depends on a chemical change to be observed
d. The smell of perfume is a physical property that can be observed at any time and not only during a chemical change