Question

why HF is not stored in glass bottles bit is kept in wax coated bottles?

Answer 1

Long in the past perhaps, but not now -HF reacts with the silica in glass (turns it into SiF4, which is a gas at room temperature or H2SiF6 which is a liquid), so you can't use glass bottlesto store it in. ... Hydrofluoric aciddissolves glass, so coating a bottlewith wax will prevent them from leaking.