Question

Ice has lower density than water because :
A . hydrogen bonding
B . hydrogen bonding and cage like structure of ice
C . bent structure of water
D . diamond structure of water

Answer 1

- Hint: We know density is defined as mass per unit volume. As the volume of substance increases , its density will decrease .Density of liquid water is one gram per ml. Liquids mostly have lower density than solids.

Complete step-by-step solution -
Lets understand about the structures of ice and water .The molecules of ice makes a cage like structure .The intermolecular interactions of molecules of ice provide a highly ordered structure but it has a loose structure where an oxygen atom is surrounded by four hydrogen atom ,among the four hydrogen atom two are covalently bonded and rest of the two hydrogen atom make hydrogen bond to the oxygen atom with unshared electron pairs. In the structure of water , The hydrogen atom shares a pair of electrons to make a covalent bond to hydrogen. The water molecules are weakly bonded together by hydrogen bonds which makes it liquid. So we can say that in ice structure there is space in the bonding and water has linear structure that is why ice has lower density ,so option B .i.e. hydrogen bonding and cage like structure of ice is the correct answer.

Note: The open structure of ice makes its density lower than water as water molecules are closer in comparison to ice so that makes the density of ice less in comparison to ice and hydrogen bonding also plays an important role in lowering the density of ice. When ice starts melting some hydrogen bond breaks and empty spaces are occupied by closely packed molecules this is the reason why ice has lower density than water.