Chemistry · General Awareness

Carbon and Fossil Fuels

1,898 Questions

Review fundamental concepts regarding carbon compounds, coal distillation, and fossil fuel formation. This segment covers the chemical properties and industrial applications of natural gas and crude oil. Practicing these questions will strengthen your chemistry foundation for general science sections.

Coal distillationPetroleum formationProperties of crude oilNatural gas applications

Carbon and Fossil Fuels Questions

Multiple choice chemistry combustion structure of flame flame combustion, fuels and flame

A lilac-coloured flame is produced on heating.

  1. Potassium in a flame

  2. Cobalt in a flame

  3. Sodium in a flame

  4. Methane in oxygen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Potassium on heating produced lilac-colured flame because on heating, an atom entities its electrons and they jump to higher energy levels. When the electron return to lower energy levels, they emit energy in the form of light. The colour produced on heating depends upon wavelength of emitted light.
Multiple choice chemistry combustion structure of flame flame combustion, fuels and flame

If you watch a burning candle carefully, you will find different colurs in the flame. Which is the hottest part of the candle flame?

  1. The middle orange part

  2. The middle, yellow part

  3. The outermost portion that is blue

  4. The innermost black zone
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The outermost portion that is blue.

The hottest part of the candle flame is the blue part, at $1670^oF$ ($1400^oC$) i.e., the outermost portion, where the flame has the most oxygen and you are getting complete combustion.

Multiple choice chemistry combustion structure of flame flame combustion, fuels and flame

The flame of the candle has three zones. The outer zone is blue, the middle zone is yellow and the inner zone is black. Which is correct regarding this?

  1. The outer zone is hottest hot.

  2. The middle zone is hottest

  3. The inner zone is least hot

  4. All the zones have same temperature
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

Candles produce light by releasing heat. A candle flame consists of three zones. Each zone has different temperatures and colors.

  • The first zone is called the Outer zone
  • The second zone is called the Middle zone
  • The third zone is called the Inner zone

The outer zone is blue in color, due to complete combustion,. This zone is the hottest zone.

The middle one is in yellow color, which is the bright part of the flame. It is moderately hot and partial combustion of fuel takes place.

The least hot region of the flame is innermost zone. This inner zone is black in color due to the presence of unburnt wax vapors.

Multiple choice solid waste and its management conservation of environment

 The rate of pyrolysis increases with 

  1. Temperature

  2. Pressure

  3. Preciptation

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Pyrolysis is the process of breaking organic compounds in the presence of heat but in absence of oxygen. The process accelerates with increase in temperature. 
So, the correct answer is 'Temperature'
Multiple choice evs how to save fuel fuels fuel and effects of burning fuel study of combustion

_____ is any material that can be made to react so that it releases chemical or nuclear energy as heat.

  1. Fossil fuel

  2. Fuel

  3. Oil

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

A fuel is any material that can be made to react so that it releases chemical or nuclear energy as heat or to be used for work. The heat energy released by reactions of fuels is converted into mechanical energy via a heat engine.

Multiple choice evs how to save fuel fuels fuel and effects of burning fuel study of combustion

What is an ideal fuel?

  1. It has high calorific value

  2. It is cheap

  3. It is readily combustible

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

An ideal fuel is cheap, readily available, easy to transport and readily combustible. It has high calorific value. It does not produce gases or residues that pollute environment.

Multiple choice evs how to save fuel fuels fuel and effects of burning fuel study of combustion

The ignition temperature of an ideal fuel should _____________.

  1. Lowest

  2. Highest

  3. Neither too high nor too low

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ideal fuel should have a proper ignition temperature, so that it can be burned easily. The ignition temperature of an ideal fuel should neither be too low nor too high. If the ignition temperature of the fuel is very low, then the fuel will catch fire too easily and hence it will be very unsafe to use it. On the other hand, if the ignition temperature is too high, then it will be very difficult to light the fuel.

Multiple choice evs how to save fuel fuels fuel and effects of burning fuel study of combustion

Which of the following has lowest ignition temperature ?

  1. LPG

  2. Petrol

  3. Coal

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

Ignition temperature is the lowest temperature at which a substance catches fire. Among the choices, LPG is a highly volatile gas with a very low ignition temperature compared to solids like coal or liquids like kerosene.

Multiple choice evs how to save fuel fuels fuel and effects of burning fuel study of combustion

Producer gas is not a good fuel because:

  1. it contains $CO$ which is poisonous
  2. it contains $CO _2$
  3. it contains $CO _2$ which does not burn
  4. it contains $N _2$ which does not burn
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The producer gas is a mixture of nitrogen and carbon monoxide. Two thirds by volume is nitrogen and one third by volume is carbon monoxide. Carbon monoxide is combustible gas in the mixture. Nitrogen is non-combustible. producer gas is not considered as good fuel because it contains Nitrogen which does not burn.


Hence, the correct option is $\text{D}$

Multiple choice evs how to save fuel fuels fuel and effects of burning fuel study of combustion

Which of the following is an ideal fuel?

  1. Coal

  2. LPG

  3. Petrol

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

An ideal gas must possess high calorific value, must have a moderate rate of combustion and must be easily available. The calorific values of coal, petrol, LPG are quite less than an ideal gas. The molecules present in an ideal gas obeys the gas laws and follows the Newtons laws of motion.


Hence, the correct option is $\text{D}$

Multiple choice evs how to save fuel fuels fuel and effects of burning fuel study of combustion

Which one of the following is used as 'clean fuel'?

  1. Petrol

  2. Mineral oil

  3. Methane

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

LPG (Liquefied Petroleum Gas) is considered a cleaner fuel compared to petrol or mineral oil because it produces fewer particulate emissions and less carbon monoxide upon combustion. Methane is also a clean fuel, but LPG is the standard answer in this context for domestic clean fuel usage.

Multiple choice evs how to save fuel fuels fuel and effects of burning fuel study of combustion

The characteristics of a ideal fuel are:

  1. it should release more energy

  2. it should be safe

  3. it should be easily transportable

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

Ideal fuel shows the following characteristics:

  • It should be  less expensive,
  • It should be easily  available,
  • It should produce a large amount of heat,
  • It can be  transported  easily
  • It has high calorific value.
  • It should  burns easily in air at a moderate rate.

Hence option D is correct.

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.