Question

NCERT CLASS IX - Science Textbook
Chapter 1 - Matter in Our Surroundings

What is the physical state of water at:

(a) 250°C
(b) 100°C

Answer 1

we know that when water get heated upto 100°C it became boiled and when it rises it changes its state liquid to gas or steam or water vapour . 
 at 100°C the water het boiled and in that time it is in the form of liquid as well as some gases .

Answer 2

Boiling point of water at normal atmospheric pressure of 1 bar or 1 atm  is 100 deg C.

Freezing point of water  at normal atmospheric pressure is 0 deg. C

Hence,  water exists as liquid  between  0 deg C  and 100 deg C.

Physical state of water at 250 deg C  =  Vapour  or  gaseous state or steam..

Physical state of water at  100 deg C  =  either as water boiling  or  water vapour
   At 100 deg C,  at normal pressure ,  liquid water exists in equilibrium with water vapour.  So both states exist.