A phenomenological theory of low-mobility liquid hydrocarbons is devel
oped which includes electron ballistic motion in the quasi-free state,
in competition with diffusion and trapping. For most low-mobility liq
uids the theory predicts consistently the effective mobility and activ
ation energy, in agreement with experiments, using quasi-free mobility
and trap density respectively as similar to 100 cm(2) v(-1) s(-1) and
similar to 10(19) cm(-3). Field dependence of mobility is theoretical
ly of quadratic type for relatively small fields, agreeing approximate
ly with experimental data for n-hexane. Electron scavenging with ''goo
d'' scavengers occurs via the quasi-free state at nearly diffusion-con
trolled rate; however the effect of large mean free path is seen clear
ly.