Question

The freezing point of water is an endothermic process.
Heat must be removed from the water to make it freeze.
A.Statement–1 is true, Statement–2 is true and statement-2 is correct explanation for statement-1
B.Statement–1 is true, Statement–2 is true and statement-2 is NOT the correct explanation for statement-1
C.Statement–1 is true, Statement–2 is false
D.Statement–1 is false, Statement–2 is true.

Answer 1

Hint: If some methods require heat, others must release heat when they take place. These are known as exothermic. So, heat needs to be removed. If heat is removed from water vapor, the gas removes heats and cools down and it condenses back into liquid water.

Complete step by step answer:
When water molecules are in the liquid phase, they are repeatedly roaming around, constantly bumping and colliding with each other. Hydrogen bonds are always being established and spilt as water molecules move past each other. At room temperature, the liquid state is separated by a relatively high average kinetic energy for the water molecules. Now, in order to slow these molecules down to lower so that the hydrogen bonds that are formed between single water molecules are no longer broken, you need to take energy out of the system. When water is in its solid state, the molecules are fixed up in position in a crystal network. The average kinetic energy of the molecules can now no longer overpower the hydrogen bonds, and so ice is formed.
If heat is removed from water vapor, the gas removes heats and cools down and it condenses back into liquid water. Continue to cool the water (by removing heat), and it becomes solid ice.
So, the first statement (statement-1) is wrong and the second statement (statement-2) is right.

Therefore, the correct answer is option (D).

Note: In exothermic processes, heat is given out and freezing of water is clearly an exothermic process in which heat is given out and not absorbed which is done during an endothermic process.