Question

Which of the following acids cannot be stored in glass?
(a) \[HF\]
(b) $HCl$
(c) ${H_2}S{O_4}$
(d) $HI$

Answer 1

Hint:First we have to find out what are the chemicals which react with the glass and what happens when the chemicals are stored in the glass, if not in the glass what are the different options where we can store these chemicals.

Complete answer:
Let’s know first what are the chemicals reacts with the glass:
Some of the chemicals only react with the glass. They are hydrofluoric acid \[HF\] , concentrated alkalis, a high temperature water which is superheated and concentrated phosphoric acid. These are the few chemicals which react with glass. But, the hydrofluoric acid \[HF\] is the one which can destroy any type of the silicate glasses.
So, from the given options, only \[HF\] cannot be stored in the glasses.
Hydrofluoric acid \[HF\] cannot be stored in the glasses because they corrode the silicates of glass and dissolve in the hydrofluoric acid.
The reaction of the hydrofluoric acid with glass is as follows:
$N{a_2}Si{O_3}(s) + 8HF(aq) \to {H_2}Si{F_6}(aq) + 2NaF(aq) + 3{H_2}O$
Hence, from the following acids, only hydrofluoric acid \[HF\] cannot be stored in glass.
Due to the high corrosive nature of the hydrofluoric acid which corrodes the glass silicates, they preferred to store in the wax coated bottles. Although having a weak acid, it is highly corrosive in nature and colourless. It is used for making different types of compounds having fluorine as constituents.

Hence, the correct option is (a) \[HF\] .

Note:
The chemicals which are highly reactive with the silicates should not use glass as the storage of that chemicals because glass are small grains of the quartz crystals made up of the molecules of the silicon dioxide and remember hydrofluoric acid \[HF\] is not a strong acid.