Question

Glass is called super cooled liquid. Give reason.

Answer 1

Glass

• Glass is a homogeneous mixture of super-cooled molten sodium silicate and calcium silicate.
• This consists of silica sand$\left({\mathrm{SiO}}_2\right)$ sodium oxide $\left({\mathrm{Na}}_2\mathrm{O}\right)$ from soda ash, calcium oxide $\left(\mathrm{CaO}\right)$from limestone/dolomite, dolomite $\left(\mathrm{MgO}\right)$ and feldspar $\left({\mathrm{Al}}_2{\mathrm{O}}_3\right).$ These ingredients are mixed in the right proportion,
• The entire batch is flown into a furnace heated to $1500°\mathrm{C}$

Glass is a super cooled liquid

• Glass is a homogeneous mixture of super-cooled molten sodium silicate and calcium silicate.
• Glass is an amorphous solid. Therefore, it is assumed liquid that is super cooled.
• Glass is often referred to as a super cooled liquid because of its amorphous nature ( a transition state between two states) that enables molecules to continue to transit in the substance.

Therefore, when glass is made the silica is cooled from its liquid state, and it does not solidifies even when the temperature is dropped below freezing point. Hence, glass is a super cooled liquid.