What does sand do when it is heated on a Bunsen burner?

Answer 1

Due to the properties of sand, when we heat it over Bunsen burner it can be used as heating buffer. The sand would absorb heat even after it is removed so we can use it similarly to a hot water bath but the sand will eventually cool down and need reheating. It is common to use this sand heat bed technique in organic laboratories or when gentle/slow heating is required.

Answer 2

When sand is heated on a Bunsen burner, it absorbs the heat and gets hot. As it continues to heat up, the sand can eventually melt into glass.