  This paper presents a millimeter wavelength aperture-synthesis study of the
spatial variations of the chemistry in the envelope around the deeply embedded
low-mass protostar L483-mm on 1000 AU (5") scales. Lines of 8 molecular species
including CN, C18O, CS, C34S, HCN, H13CN, HCO+ and N2H+ have been observed
using the Owens Valley Radio Observatory Millimeter Array. Continuum emission
at 2.7-3.4 millimeter is well-fit by a pure envelope model down to the
sensitivity of the interferometer without introducing a disk/compact source, in
contrast to what is seen for other protostars. A velocity gradient in the
densest material is traced by HCN, CS and N2H+, and is perpendicular to the
large-scale CO outflow, with a pattern consistent with rotation around a 1
solar mass central object. Velocity gradients in the propagation direction of
the outflow suggest a clear interaction between the outflowing material and
"quiescent" core. The C18O observations are fit with a "drop" abundance profile
where CO is frozen-out in a region of the envelope with temperatures lower than
40 K and densities higher than 1.5e5 cm^{-3}, which is also required to
reproduce single-dish observations. The N2H+ emission strongly resembles that
of NH3 and is found to be absent toward the central continuum source. This is a
direct consequence of the high CO abundances in the inner region as illustrated
by a chemical model for the L483 envelope. The observed CN emission forms a
spatial borderline between the outflowing and quiescent material probed by,
respectively, HCO+ and N2H+, and also shows intermediate velocities compared to
these two species. A scenario is suggested in which CN is enhanced in the walls
of an outflow cavity due to the impact of UV irradiation either from the
central protostellar system or related to shocks caused by the outflow.
