Silica gel is slightly acidic. Will this cause an acidic compound to run faster or slower in a given mobile phase vs a similar basic compound? Why? Solution SiO2 is an acidic compound.when SiO2 in water gives acid H2SiO3. In acidic or basic condition, mainly depends upon polarity. Polar compounds easily hydrogen bonding with silica gel and make highly mobile phase polar. Polar.compounds bind with silica gel easily whereas nonpolar compounds easily will come in the column chromatography..