Sugar burns with a yellow sooty flame due to the incomplete combustion of carbon and hydrogen present in its molecular structure. When sugar is heated, it breaks down into carbon, water, and other compounds, and the carbon particles form soot. The yellow color of the flame is primarily caused by the incandescence of these tiny carbon particles, which emit light as they are heated. Incomplete combustion occurs because there is often insufficient oxygen to fully oxidize the carbon, resulting in the characteristic yellow, sooty flame.
For the same reason anything else burns with a sooty flame--not enough oxygen. What happens is, the outside of the flame gets all the air it wants, and the little oxygen that makes it through isn't enough to properly combust the fuel. If you mix air with the fuel before you burn it, as is done in a carburetor or a welding torch, you don't get a sooty flame.
Hydrocarbons like alkanes (e.g. propane, butane) are organic compounds that can burn with a sooty flame due to incomplete combustion, which produces carbon particles.
candles burn with a yellow flame because its an incomplete combustion
You get and orange - yellow colour.
Bright yellow :: This is the sodium ions. Any sodium compound will give a flame test colour of yellow/
Orangish yellow
Manganese, when burning, produces a yellow-green flame.
A strong yellow color, from sodium
Candle burns with a yellow flame because its an incomplete combustion. The temperature of the flame also relates to its colour and also the trace metal ions present will influence the flame colour.
Generally, the more oxygen supplied to a flame, the hotter and bluer the flame is.Wick stoves need to be hot, so they are designed to allow lots of oxygen to get to the flame, which also makes it bluer.Lamps just need to be bright, so the oxygen input is regulated by valves in order to achieve a more yellow, cooler flame.
Lime water typically burns with a yellow or greenish flame.
The blue flame is really hotter than the yellow flame. If you put your hand over a blue flame and skim through it, it would burn you but if you put it over a yellow flame it wouldn't burn you that much.