Question

What is the physical state of water at ${250^0}C$ ?
a.) Liquid
b.) Solid
c.) Gaseous
d.) None of the above

Answer 1

Hint: In order to solve this problem we will study what are physical states and further we will study what are the different physical states that can be achieved by water and also we will study what are the different conditions required for existence of that state of the water on the basis of our study we will select the physical state that the water takes at the given temperature.

Complete step by step answer:
To find the physical state of the water at ${250^0}C$ .
First let us study about the different physical states.
Generally there are 3 physical states of existence in nature and they are solid, liquid and gaseous states. Further the scientists are carrying out research on plasma state.
So, in nature water exists in all the three physical states at different temperatures and pressures.

We will see the states at basic atmospheric pressure which is 1 atm of pressure.
At ${0^0}C$ and below ${0^0}C$ temperature:
At ${0^0}C$ and below ${0^0}C$ temperature water is present in solid state which is also known as ice, so ${0^0}C$ is also known as the freezing point of the water.

Above ${0^0}C$ and below ${100^0}C$ temperature:
Above ${0^0}C$ and below ${100^0}C$ temperature water is present in the liquid state which is also known as common water.

Above ${100^0}C$ temperature:
Above ${100^0}C$ temperature water is present in the gaseous state which is also known as water vapour. So, ${100^0}C$ is also known as the boiling point of the water.
On the basis of above understanding we can see that as ${250^0}C$ is greater than ${100^0}C$ temperature.
Hence, at ${250^0}C$ water exists in vapour form or gaseous state.
So, the correct answer is “Option C”.

Note: In order to solve such types of problems students must remember the freezing point and the boiling point of the water and must also remember about the phase transformation from one state to another. The students must take extra care when the temperature asked is at the midpoint of the transformation which is at the freezing point and the boiling point.