With reference to the 'Middle Zone' of a candle flame, consider the following statements: 1. It is the non-luminous zone of the flame. 2. It is the zone of partial combustion. 3. It is yellow in colour. Which of the statements given above is/are correct?

Correct Option The correct option is (c). Explanation A candle flame consists of three distinct zones based on the availability of oxygen and the extent of combustion: the innermost zone (dark), the middle zone (luminous), and the outer zone (non-luminous). Statement-wise Analysis: - Statement 1 is Incorrect. The middle zone is the luminous zone of the flame, not the non-luminous zone. The non-luminous zone refers to the outermost part of the flame where complete combustion occurs, usually appearing blue. - Statement 2 is Correct. The middle zone is characterized by a limited supply of oxygen. Consequently, the wax vapours undergo partial combustion rather than complete combustion. - Statement 3 is Correct. Due to partial combustion, unburnt carbon particles are produced. These particles become hot and emit light, giving the middle zone a characteristic yellow colour. Key Takeaway: The middle zone of a candle flame is the zone of partial combustion, is luminous (yellow), and is moderately hot compared to the outer zone.

With reference to the 'Middle Zone' of a… - NCERT Class 8 Science MCQ

NCERT Class 8 Science — Chapter 2: Combustion and flame

mcqeasy

With reference to the 'Middle Zone' of a candle flame, consider the following statements:

It is the non-luminous zone of the flame.
It is the zone of partial combustion.
It is yellow in colour.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Science - class 8 · Page 9

Options

A1 and 2 only
B2 only
C2 and 3 only
D1, 2 and 3

Did you get this right?

Solution

Correct Option

The correct option is (c).

Explanation

A candle flame consists of three distinct zones based on the availability of oxygen and the extent of combustion: the innermost zone (dark), the middle zone (luminous), and the outer zone (non-luminous).

Statement-wise Analysis:

Statement 1 is Incorrect. The middle zone is the luminous zone of the flame, not the non-luminous zone. The non-luminous zone refers to the outermost part of the flame where complete combustion occurs, usually appearing blue.
Statement 2 is Correct. The middle zone is characterized by a limited supply of oxygen. Consequently, the wax vapours undergo partial combustion rather than complete combustion.
Statement 3 is Correct. Due to partial combustion, unburnt carbon particles are produced. These particles become hot and emit light, giving the middle zone a characteristic yellow colour.

Key Takeaway:

The middle zone of a candle flame is the zone of partial combustion, is luminous (yellow), and is moderately hot compared to the outer zone.

Your note

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