Question

The ground glass stopper is often seen to get stuck in the neck of glass bottles containing aq $NaOH$ solution This is due to:
(A) Formation of solid $N{a_2}C{O_3}$ around the neck of the bottle due to $NaOH$ reacting with atmospheric $C{O_2}$
(B) Formation of solid $N{a_2}Si{O_3}$ around the neck of the bottle
(C) Creation of partial vacuum due to highly hygroscopic nature of $NaOH$
(D) High coefficient of thermal expansion of glass

Answer 1

Hint: It is unwise to put sodium hydroxide, or any alkali solution in a glass bottle with a glass stopper without oiling the stopper with a little petroleum jelly, because the alkali can react with the carbon dioxide in the air producing carbonate crust which might block the stopper.

Complete step by step solution:
Sodium hydroxide attacks glass, making sodium silicate, which is also known as waterglass and is used as a cement. It depends on the $NaOH$ concentration and how long the bottle is unused. However, it can be difficult to get open again The ground glass stopper is often seen to get stuck in the neck of glass bottles containing aq $NaOH$ solution this is due to formation of solid $N{a_2}Si{O_3}$ around the neck of the bottle.
$2NaOH(aq) + Si{O_2} \to N{a_2}Si{O_3}(s) + {H_2}O$
Here, $N{a_2}Si{O_3}$ fuses with glass so the ground glass stopper is often seen to get stuck in the neck of a glass bottle containing a $NaOH$ solution.

Note: We would use a polypropylene stopper instead of glass stopper. Polypropylene is a type of thermoplastic polymer and is used in a variety of applications. With the use of polypropylene we can stop the formation of the solid $N{a_2}Si{O_3}$ around the neck and the stopper is not seen to get stuck in the neck of glass containing a $NaOH$ solution.