_____ combustion is the reason for the blue colour in Bunsen flame.

Options

A. Incomplete
B. Complete
C. Rapid
D. Spontaneous

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the type of combustion that causes the blue color in a Bunsen flame.

2. **Identifying Bunsen Flame Characteristics**: The Bunsen flame is known for its distinct blue color. This color is an important indicator of the type of combustion occurring.

3. **Types of Combustion**: There are different types of combustion:
- **Complete Combustion**: Occurs when there is a sufficient supply of oxygen, resulting in a blue flame.
- **Incomplete Combustion**: Occurs with limited oxygen supply, leading to a yellow flame.
- **Rapid Combustion**: Involves burning quickly and producing heat and light but does not specifically relate to the flame color.
- **Spontaneous Combustion**: Occurs without external heat but is not related to the flame color.

4. **Analyzing the Options**:
- **Option 1: Incomplete Combustion** - This results in a yellow flame, so it is incorrect.
- **Option 2: Complete Combustion** - This occurs with excess oxygen and results in a blue flame, making it the correct answer.
- **Option 3: Rapid Combustion** - This refers to the speed of combustion and does not determine flame color, so it is incorrect.
- **Option 4: Spontaneous Combustion** - This type of combustion occurs without external heat and is not related to flame color, making it incorrect.

5. **Conclusion**: The correct answer is **Complete Combustion**, as it is the reason for the blue color in a Bunsen flame.

**Final Answer**: Complete combustion is the reason for the blue color in Bunsen flame.

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