Tag: combustion and flame

Quizzes (8) Questions (9)

Questions Related to combustion and flame

Multiple choice chemistry combustion and flame fuels fuel and effects of burning fuel study of combustion

While cooking, if the bottom of the vessel is getting blackened on the outside, it means that __________.

  1. the food is not cooked completely

  2. the fuel is not burning completely

  3. the fuel is wet

  4. all of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

While cooking, if the bottom of the vessel is getting blackened on the outside, it means that the fuel is not burning completely. When the fuel burns completely giving a blue flame, the bottom of the vessel remains clean. 


When the fuel does not burn completely then a sooty flame appears which makes the bottom of the utensil black. It is due to the air holes, which are getting blocked and the fuel does not burn completely.

Multiple choice chemistry combustion and flame fuels fuel and effects of burning fuel study of combustion

Which of the following is most harmful for human body?

  1. CO
  2. $CO _2$

  3. Oxides of nitrogen

  4. Lead compounds
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lead compounds are heavy metal toxins that cause severe, long-term damage to the nervous system, kidneys, and blood, making them significantly more harmful than common atmospheric pollutants like CO or CO2 in terms of cumulative toxicity. While CO is acutely toxic, lead compounds are persistent environmental poisons.

Multiple choice chemistry combustion and flame fuels fuel and effects of burning fuel study of combustion

Why is CNG a cleaner fuel?

  1. No particulate emission

  2. Releases very less amounts of sulphur and nitrogen oxides

  3. No emission of ash

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

C.N.G (compressed natural gas) is a cleaner fuel because it causes less pollution by emitting fewer pollutants like carbon dioxide, carbon monoxide, sulphur dioxide, nitrogen dioxide, particulate matter, unburned hydrocarbons etc.

Multiple choice chemistry combustion and flame structure of flame flame combustion

What is the maximum possible temperature( in $^0 C$) of a Bunsen burner flame? Assume that the gas is pure methane and that it is pre-mixed with sufficient air to permit complete combustion.

  1. 1500

  2. 4000

  3. 5000

  4. 1100
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The adiabatic flame temperature of a methane-air flame is approximately 1900-2000 degrees Celsius. Among the provided options, 1500 is the most reasonable estimate for a standard Bunsen burner flame, as heat losses prevent it from reaching the theoretical maximum.

Multiple choice chemistry combustion and flame structure of flame flame combustion

Burning of coal and wood causes  _____________.

  1. pollution of air

  2. decrease of non-renewable source of energy

  3. both (a) and (b)

  4. neither (a) or (b).
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Burning of coal and wood causes air pollution and because of burning of coal and wood there is decrease in amount of non-renewable sources. 

Multiple choice chemistry combustion and flame structure of flame flame combustion

The zone of no combustion is _______.

  1. The middle zone

  2. Outermost zone

  3. The base of the flame

  4. Innermost zone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Innermost zone is the zone of no combustion. It is also called as dark zone which is formed around the wick of the candle flame.

Multiple choice chemistry combustion and flame structure of flame flame combustion

Substance which vaporize during burning gives ____________.

  1. sound

  2. flame

  3. combustion

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Substances which vaporize during burning gives flame. For example, combustion of kerosene oil produces a flame. On the other hand, certain substances like coal do not vaporize and hence does not produce a flame.