Can you wear a Mithral Chain over Snakeskin Tunic and have their effect stack?
Snakeskin Tunic: A snakeskin tunic is a tight, form-fitting shirt crafted from the scales of a giant snake. When worn, it grants a +1 armor bonus to AC, a +2 enhancement bonus to Dexterity, and a +2 resistance bonus on saving throws against poison.
Mithral Shirt: This extremely light chain shirt is made of very fine mithral links. The armor has an arcane spell failure chance of 10%, a maximum Dexterity bonus of +6, and no armor check penalty. It is considered light armor.