  The X-ray polarization properties of the reflection nebulae in the Galactic
center inform us about the direction of the illuminating source (through the
polarization angle) and the cloud position along the line of sight (through the
polarization degree). However, the detected polarization degree is expected to
be lowered because the polarized emission of the clouds is mixed with the
unpolarized diffuse emission that permeates the Galactic center region. In a
real observation, also the morphological smearing of the source due to the
point spread function and the unpolarized instrumental background contribute in
diluting the polarization degree. So far, these effects have never been
included in the estimation of the dilution. We evaluate the detectability of
the X-ray polarization predicted for the MC2, Bridge-B2, G0.11-0.11, Sgr B2,
Sgr C1, Sgr C2, and Sgr C3 molecular clouds with modern X-ray imaging
polarimeters such as the Imaging X-ray Polarimetry Explorer (IXPE) and the
Enhanced X-ray Timing and Polarimetry mission (eXTP). We perform realistic
simulations of X-ray polarimetric observations considering (with the aid of
Chandra maps and spectra) the spatial, spectral, and polarization properties of
all the diffuse emission and background components in each region of interest.
We find that in the 4.0-8.0 keV band, where the emission of the molecular
clouds outshines the other components, the dilution of the polarization degree,
including the contribution due to the morphological smearing of the source,
ranges between $\sim$19\% and $\sim$55\%. We conclude that for some distance
values reported in the literature, the diluted polarization degree of
G0.11-0.11, Sgr B2, Bridge-B2, Bridge-E, Sgr C1, and Sgr C3 may be detectable
in a 2 Ms long IXPE observations. The enhanced capabilities of eXTP may allow
detecting the 4.0-8.0 keV of all the targets considered here.
