# Why are acid amides insoluble in water?

$\text{Acetamide}$, ${H}_{2} N \left(O =\right) C - C {H}_{3}$ has an aqueous solubility of $2000 \cdot g \cdot {L}^{-} 1$....Because it is a primary amide, with a very short hydrocarbyl tail, this solubility may be rationalized. As the hydrocarbyl tale gets longer we would expect a decrease in solubility. However, the case in point is very water-soluble, inasmuch as it can engage in hydrogen-bonding with the water solvent.