Why is there a large difference in the boiling points of butanal and butan-1-ol ?

There is a large difference in the boiling points of butanal and butan - 1 - ol due to

Though butanol and butanal have the same solubility in water, there is large difference in thelr boiling points. Why?

Butan-1-ol and Butan-2-ol are

Arrange the following in the increasing order of the boiling points. Butanal, diethyl ether, butan-1-ol,pentane