Final answer:
The statement that a blue flame indicates a great amount of excess air is false. A blue flame represents optimal air mixture leading to complete combustion and a hotter flame compared to yellow or red flames, which are indicative of incomplete combustion with a lower temperature.
Step-by-step explanation:
The statement that a blue flame indicates a great amount of excess air is false. In combustion processes, such as those in a Bunsen burner or a stove, a blue flame actually signifies that the gas is burning efficiently, with virtually complete combustion, meaning that there is an optimal amount of air (oxygen) for the fuel being burned. By contrast, a yellow or red flame indicates incomplete combustion, often because of a lack of oxygen, which can result in soot and other unburned carbon particles.
The color of a flame is also an indicator of its temperature. A blue flame is generally hotter than a yellow flame. This is because the complete combustion that produces a blue flame also releases more energy, leading to a higher temperature. An example is the difference between the blue flame of a Bunsen burner and the yellowish flame of a peach-scented candle; the former is hotter than the latter.
Question and Answer Examples
- Which flame has a higher temperature? The flame of a Bunsen's burner is blue and indicates a higher temperature compared to the yellowish flame of a peach-scented candle.
- Two flames on a stove, one red and the other blue; the blue flame is hotter, as indicated in choice (d) of the question - because blue light has a higher frequency.
- Regarding the pressure of the gas in the hot-air balloon, it is critical to note that it must be less than or equal to the pressure of the atmosphere outside to allow the balloon to rise.
- As gas heats up, as mentioned in choice (d), turbulence and friction don't cause the gas to glow. Rather, the glow of a flame is due to the heat itself inciting the emission of light from particles within the flame.