The hydrogen bond is a secondary bond formed between a hydrogen (attached to an highly electronegative element ,: F, O or N) and another atom of an highly electronegative element ,: F, O or N.
In case of water hydrogen bond helps water
a) to dissolve certain substances which can make hydrogen bond
b) it makes it liquid and room temperature unlike H2S which is a gas at room temperature due to absence of hydrogen bond
c) higher volume and low density of ice as compared to liquid water. Due to hydrogen bond ice forms open cage like structure which increases its volume and decreases its density. Thus water expands on freezing
So in absence of hydrogen bond Water would not expand when it freezes.
