From the work of Le Chatelier [1884], it is well known that chemical reactions that exhibit a change in volume are sensitive to the ambient pressure of the reaction. Increasing the pressure will alter the ratio of reaction products to reactants. If the change in volume is constrained to occur at a surface, then such reactions can result in residual stresses that affect the strength of the solid. These effects are applicable to silica glass, which increases in volume when reacting with water. In this paper, we discuss the possibility of using this effect to strengthen silica glass. Using a modification of Le Chatelier's theory to handle applied stresses, we show that water penetration into the surface of silica glass can yield sufficient residual stress to increase the strength of silica glass into the GPa range. Applying these ideas to recent data published by Lezzi et al., we are able to attribute the strengthening they observe to a water/silica reaction under an applied tensile stress.