The boiling points of amines and their corresponding alcohols and acids vary in the order

• Nitrogen is less electronegative than oxygen. So, $\mathrm{N}-\mathrm{H}$ bond is less polar than $\mathrm{O}-\mathrm{H}$ bond.

Thus, alcohol and acid have more hydrogen bonding than amines.

Also, carboxylic acids have more extensive H-bonding due to its association nature.

Since, $\mathrm{H}$-bonding $\mathrm{\alpha }$ boiling point

Thus, Boiling point order will be,

${\mathrm{RCH}}_2{\mathrm{NH}}_2<{\mathrm{RCH}}_2\mathrm{OH}<\mathrm{RCOOH}$