Write the structures of all the isomeric amines represented by formula ${\mathrm{C}}_5{\mathrm{H}}_{13}\mathrm{N}$ that evolve nitrogen gas on treatment with sodium nitrite and dilute hydrochloric acid.

Give the IUPAC name of ${\left({\mathrm{CH}}_3\right)}_2\mathrm{N}-{\mathrm{C}}_2{\mathrm{H}}_5$.

Write the IUPAC name of 

Write the IUPAC names of the following compounds,

.

Write the IUPAC names of the following compounds: ${\mathrm{C}}_6{\mathrm{H}}_5-\mathrm{N}{\left({\mathrm{CH}}_3\right)}_2$.

A secondary amine is a/an _______.