Question

Mention the properties of silica due to which it is used as a sand bath in the laboratory.

Answer 1

The compound made up of oxygen and silicon is known as silica. The general formula of silica is ${\left( {{\text{Si}}{{\text{O}}_{\text{2}}}} \right)_{\text{n}}}$. Silica sand is the sand that contains silicon dioxide in a high amount. Silicon dioxide is chemically inert. It has a high melting point.

Complete Step by step answer: Silica is silicon dioxide which is also known as quartz.
A container filled with heated silica sand is known as a sand bath. It is laboratory equipment.
In a sand bath, a beaker filled with sand is placed over a heater or hot plate. Then the vessel in which the reaction mixture is filled is placed in a beaker. As the sand is heated it passes the heat to the reaction vessel.
The properties of silica are as follows:
Silica is chemically inert.
It has a high melting point, so stable at high temperatures.
Silica sand has a high thermal capacity.
It is non-combustible.
So, due to chemical inertness, high thermal capacity, and stability at high-temperature silica is used as a sand bath in the laboratory.
Silica sand baths are used for roasting. Heating at a high temperature in presence of air is known as roasting. Silica can withstand high temperatures, so it is used for roasting.

Note: Direct supply of heat requires stirring so all part of the reaction mixture can be heated equally. Sand conducts even at all parts of the reaction vessel. A sand bath is very easy to clean just by un-filling the container. The reaction vessel is generally made up of glass, due to temperature change there is always a risk of cracking. The use of a sand bath minimizes the risk of cracking.