Question

Why hf acid is stored in wax coated glass bottles?

Answer 1

Hf is hydrogen fluroide which exist mainly as gas
Although the flourine is very electronegative in nature than other halogens but it has very less atomic radius or it's size is smaller so it shares stronger bonds with hydrogen
due to stronger bonds it become a weak acid which is very reactive with glass and a little reactivity towards many metals make it student wax coated glass bottles so it cannot react with glass

hope it helps

#MK

Answer 2

This is because HF does not attack wax but reacts with glass.It dissolves SiO2 present in glass forming hydrofluorosilicic acid.

SiO2 + 6HF → H2SiF6 + 2H2O