Question

Why density of ice maximum at 4℃ ?

Answer 1

Hey friend..!! here's your answer
_________________________

At 4℃ the cage like structure of ice get collapsed and few hydrogen bonds gets breaks due to which the vacant space which is entrapped by air , is now occupied by water . Hence its density get increase and ice get drowned in H20

___________
#Hope its help

Answer 2

Heya  friend!   Here's the answer to your question :-  H2O (water )exists in cage form in its solid state ie. Ice.  This cage like structure has intermolecular spaces to trap gases and it's formation will thus lead to increase in volume. Similarly, if we break down the cage structure, the volume enclosed will decrease. Now at 4°Celsius,  what happens is that the entire cage -like structure is broken down (due to continuous heating till 4°C, the kinetic energy of molecules increases and this cage like structure finally  breaks when it attains a temperature of 4°C  completely ) This results in decrease in it's volume and thus results in maximum density. (As density is inversely proportional to the volume ) Therefore, density of ice is maximum at 4°Celsius.    Hope that helps you! :)