Question

which zone of candle give yellow flame and which type of combustion takes place in this zone?? please answer fast I need it urgently

Answer 1

A flame consist of three zones.These are Innermost zone,middle zone,outer zone.The three zones of a flame have different colours and different temperature.
1) The Innermost zone of a flame is dark or black
2)The middle zone of a flame is yellow
3)The outer zone of a flame is blue:It is a non-luminous zone
the yellow flame is bright and luminous.
gives less heat because of incomplete combustion.

Answer 2

The zone occurring after the non-luminous zone is the luminous zone. It is a region where the incomplete combustion takes place. And a large amount of heat is generated. All the unvapourised gases and the molten wax will be burnt in this zone. There will be vigorous burning action taking place. So the molten wax further vaporises in the existence of vapor particles and wax. The flame is yellowish in colour.