The hottest part of the Bunsen burner is

Options

A. blue zone
B. zone of complete combustion
C. zone of partial combustion
D. all parts of the flame are equally.

Answer

To determine the hottest part of a Bunsen burner, we can analyze the different zones of the flame produced by the burner. Here’s a step-by-step solution:

### Step 1: Identify the Zones of the Bunsen Burner Flame
The Bunsen burner flame consists of different zones, each with distinct characteristics:
- **Blue Zone (Non-luminous Zone)**
- **Luminous Zone (Yellow Zone)**
- **Outer Zone**

### Step 2: Understand the Blue Zone
The blue zone is also known as the non-luminous zone. This part of the flame is characterized by:
- A blue color
- Complete combustion of the gas
- Higher temperatures compared to other zones

### Step 3: Identify the Characteristics of the Luminous Zone
The luminous zone is the yellow part of the flame and has the following features:
- It is called the zone of partial combustion.
- It appears yellow due to the presence of unburnt carbon particles.
- It is moderately hot compared to the blue zone.

### Step 4: Compare the Temperatures of the Zones
- The blue zone (non-luminous zone) is the hottest part of the flame due to complete combustion.
- The luminous zone is cooler than the blue zone because of partial combustion.

### Conclusion
Based on the analysis, the hottest part of the Bunsen burner is the **blue zone**, which is also referred to as the zone of complete combustion.

### Final Answer
The hottest part of the Bunsen burner is the **blue zone** (non-luminous zone).

---