Which part of the Bunsen burner flame is the hottest?A. the black partB. the blue flameC. the yellow flameD. none of the above

Analyzing the Question

To determine which part of the Bunsen burner flame is the hottest, we need to understand the characteristics of each flame color produced: the blue flame, the yellow flame, and the black part (often indicating incomplete combustion).

Relevant Concepts

1. Bunsen Burner Flame Colors:
   • Blue Flame: Indicates complete combustion of the gas, producing a hotter flame due to efficient mixing of gas and air.
   • Yellow Flame: Indicates incomplete combustion, which produces soot and is cooler than the blue flame.
   • Black Part: Typically represents unburned carbon particles and is not a distinct flame color.

Analysis and Details

• The blue flame is hotter than both the yellow flame and the black part because it generates more heat through optimal combustion of the fuel.
• The yellow flame produces soot and is cooler due to the lack of sufficient oxygen for complete combustion.

Conclusion

Based on the combustion efficiency and flame color properties, the hottest part of a Bunsen burner flame is the blue flame.

Final Answer

B. the blue flame