Video Transcript
What color flame will a Bunsen burner have if the air hole is fully open?
To identify the color of a Bunsen burner’s flame when the air hole of the burner is fully open, let’s first review the parts of a Bunsen burner and how it works. A Bunsen burner is used in the lab to heat substances. A Bunsen burner works by combustion of a gas, which is fed through the Bunsen burner from a gas tap connected to the burner by tubing. Gases such as methane or mixtures of butane and propane are used as fuel for this combustion. The Bunsen burner can be lit with a splint or a match to start the combustion of the gas and produce the flame that is used to heat substances.
A Bunsen burner sits on a flat base for stability and along the barrel, or also called chimney of the Bunsen burner. There is an adjustable collar. This collar can be turned to adjust whether the air hole is open or closed. This alters the amount of air from the surroundings that can enter the Bunsen burner, which provides oxygen to support the combustion of the gas. If the color is turned to close or partially close the air hole, there’s limited oxygen provided to the combustion reaction, resulting in incomplete combustion. This will produce a yellow flame from the Bunsen burner. This is sometimes referred to as the safety flame of a Bunsen burner, since the flame is a lower temperature due to the incomplete combustion.
If the collar is turned to fully open the air hole, more oxygen is permitted to enter the Bunsen burner to support complete combustion of the gas. This will cause the Bunsen burner to produce a blue flame. This roaring blue flame, which is called such since it sometimes produces a roaring sound, results from complete combustion and thus occurs at very high temperatures.
Therefore, the color flame a Bunsen burner will have if the air hole is fully open is a blue flame.
