Is a white flame hotter than blue?
Note that a blue propane flame is hotter than a yellow one, but this is just due to efficient combustion, and the difference is likely in the hundreds of degrees Kelvin, not thousands. White fire might be something extremely hot, but it's more likely a mixture of several emission spectra.
Color also tells us about the temperature of a candle flame. The inner core of the candle flame is light blue, with a temperature of around 1800 K (1500 °C). That is the hottest part of the flame. The color inside the flame becomes yellow, orange, and finally red.
- Cool flame. Cool flame is a flame having maximal temperature below about 400 °C (752 °F). It is usually produced in a chemical reaction of a certain fuel-air mixture.
- The outer flame is a dark transparent blue. The inner flame is lighter, opaque in color, and comes to a sharp tip inside the outer flame. Just in front of that lighter flame is the “sweet spot,” or the hottest part of the flame. Use this point to quickly heat metal and flow solder.
- The hottest thing that we know of (and have seen) is actually a lot closer than you might think. It's right here on Earth at the Large Hadron Collider (LHC). When they smash gold particles together, for a split second, the temperature reaches 7.2 trillion degrees Fahrenheit. That's hotter than a supernova explosion.
Determining the hottest part of the Bunsen burner using a paper clip and match. Notice that the paperclip glows red hot at the top of the inner cone of the flame, At the bottom of the Bunsen burner it is much cooler.
- Air hole closed. A yellow flame is produced, which transfers less heat energy than the blue flame. The yellow flame is brighter than the blue flame because the specks of carbon glow when heated.
- As soon as the gas tap is open place your lighted match about five centimetres directly above it. The Bunsen will light to give a yellow safety flame. A lighted Bunsen Burner with its air holes closed giving a yellow safety flame. The more the air holes are open, the more fierce the Bunsen flame.
- Color also tells us about the temperature of a candle flame. The inner core of the candle flame is light blue, with a temperature of around 1800 K (1500 °C). That is the hottest part of the flame. The color inside the flame becomes yellow, orange, and finally red.
The hottest parts of a candle flame are actually the blue, almost invisible area near the base, where oxygen is drawn in, and the blue/white part around the edge, where the flame meets the oxygen-rich air all around it. The flame gets progressively cooler as you move in from the outside edge toward the wick.
- In a burning candle, there are both physical and chemical changes. The melting of the solid wax to form liquid wax and the evaporation of liquid wax to form wax vapour are physical changes. The wax vapour reacts with oxygen in the air to form new substances including carbon dioxide and ash.
- Determining the hottest part of the Bunsen burner using a paper clip and match. Notice that the paperclip glows red hot at the top of the inner cone of the flame, At the bottom of the Bunsen burner it is much cooler.
- When you light a candle, the heat of the flame melts the wax near the wick. This liquid wax is then drawn up the wick by capillary action. The heat of the flame vaporizes the liquid wax (turns it into a hot gas), and starts to break down the hydrocarbons into molecules of hydrogen and carbon.
Updated: 21st November 2019