Why does the color of sugar turns black when heated in a dry test tube for sometime? Is it thermal decomposition?

2 Answers
May 26, 2015

Well the very basic explanation would be that the sugar caramelises.
So the sugar turns to caramel.

A more complex explanation

May 29, 2015

Yes, it is a thermal decomposition reaction. The black stuff you see is mainly carbon. There will be some water vapour released. Here is an equation for the thermal decomposition of sucrose.

#"C"_12"H"_22"O"_11 + "heat" ##rarr##"12C" + "11H"_2"O"#