The model shows the potential of zero charge, pzc for short, depends on metal-water chemical interactions. We introduce δ𝜇 to characterize the chemical potential difference between water dipoles of 𝛼 w = 0° and that of 𝛼 w = 180°, where 𝛼 w is the angle between water dipole direction and the local electric field. It is found that the pzc becomes higher (lower) when 𝛿𝜇 > 0 (<0). In addition to a shift in the pzc, the first-layer water molecules also dramatically elevate the double-layer capacitance. Equivalently, it means that the first-layer water molecules contribute a negative capacitance component in series with other components, which is a known effect. However, the formula derived in this work to describe this effect, Eq.( ), is, to my knowledge, a new contribution. The model also shows chemisorption-induced dipole moment could lead to a new valley of the capacitance curve, and the capacitance in the valley could take negative values.