Question

1. draw a diagram of a correct bunsen burner flame and label the hottest spot.

Explanation:

To draw the Bunsen burner flame (when the air hole is open, producing a non - luminous, hot flame):

1. Flame Structure: The Bunsen burner flame has three main regions. The inner cone (also called the blue cone) is where the gas and air mix but haven't fully combusted yet. Surrounding the inner cone is the outer cone, which is the region of complete combustion. Above the outer cone, there is a less - defined, almost invisible region of further combustion and heat dispersion.
2. Hottest Spot: The hottest part of the Bunsen burner flame is at the tip of the inner blue cone (or just above the inner cone, within the outer cone's base). This is because this is the area where the combustion reaction is most intense as the fuel - air mixture is fully reacting here.

To draw the diagram:

• Draw the Bunsen burner base with the gas inlet and the air hole (open).
• Draw the inner blue cone (a smaller, more concentrated cone - shaped region near the burner opening).
• Draw the outer cone (a larger, more diffuse cone - shaped region surrounding the inner cone).
• Label the tip of the inner cone (or the area just above it within the outer cone) as the "Hottest Spot" (usually around \(1500^{\circ}\text{C}\) in this region due to complete and efficient combustion).

Answer:

The Bunsen burner flame (with open air hole) has an inner blue cone (unburnt gas - air mixture) and an outer cone (complete combustion). The hottest spot is at the tip of the inner blue cone (or just above it in the outer cone). A simple diagram can be represented as:

        /\
       /  \
      /    \  <-- Outer cone (complete combustion)
     /      \
    /        \
   /          \
  /            \
 /              \
/________________\  <-- Burner opening
 \              /
  \            /
   \          /
    \        /
     \      /  <-- Inner blue cone (gas - air mixture)
      \    /
       \  /
        \/
(Hottest spot at the tip of the inner cone)

Label the "Hottest spot" at the tip of the inner blue cone (or the area just above it in the outer cone).