Alkalis attack the silica directly while acids attack the alkali in the glass. When an alkali solution attacks a glass surface, the surface simply dissolves.

Does acid affect glass?

Glass is not affected by acid as it has a very strong and stable atomic structure. This is because the most common material in glass, silicon dioxide, is a particularly non-reactive substance due to its strong chemical bonds, making glass highly resistant to most acids.

What chemicals can damage glass?

While glass provides excellent resistance to most acids, there are three types which cause significant damage – hydrofluoric acid, phosphoric acid, and phosphorus acids. When glass is attacked by these acids, especially when they are concentrated solutions, corrosion can occur quickly.