Many common weak bases are derivatives of nh₃, where one or more of the hydrogen atoms have been replaced by another substituent. such reactions can be generically symbolized as

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.