ch - combustion

What are the main features of the NCF in the lesson?

Activity-based learning, class discussions, higher order thinking, strengthening values, discovery-based learning, digital literacy, and real-life situations.

What substance does combustion require to liberate heat and light?

Oxygen.

What is a combustible substance?

A substance that can catch fire and burn, such as paper, wood, and kerosene.

What happens during complete combustion of methane?

Carbon dioxide and water are formed, along with energy being released.

What is the byproduct of incomplete combustion of methane?

Carbon monoxide, water, and energy.

What are the three necessary conditions for combustion to occur?

Presence of a combustible substance, presence of a supporter of combustion (like oxygen), and heating the combustible to its ignition temperature.

What is an example of an inflameable substance?

Petrol, kerosene, alcohol, and LPG.

What is spontaneous combustion?

A type of combustion where a material bursts into flames without the application of heat.

What type of combustion is characterized by a rapid release of heat and light?

Rapid combustion.

Why might water not extinguish certain types of fires?

It does not work on oil or petrol fires as they float on water and continue to burn.

What are foam fire extinguishers effective for?

Fires caused by solids and liquids.

What kind of flame is produced when there is a complete combustion with adequate oxygen?

A non-luminous or blue flame.

What factors determine if a substance is a good fuel?

Low ignition temperature, high calorific value, moderate rate of combustion, safety in storage and handling, low pollution, and low residue after burning.

What is calorific value?

The amount of heat liberated when one kilogram of a combustible substance is completely burnt in sufficient oxygen.

What are the impacts of burning fuels on the environment?

Releases carbon dioxide, contributes to global warming, can cause air and water pollution, and results in habitat destruction due to industrial activities.

What is the purpose of a fire extinguisher?

To remove one of the three conditions necessary for combustion to occur.

What happens to a candle flame in a closed space with insufficient oxygen?

The flame turns yellow and incomplete combustion occurs.

How does the structure of a candle flame vary?

It has different zones: non-luminous zone, luminous zone, dark zone, and blue zone with varying temperatures and combustion characteristics.

What is the significance of the ignition temperature in combustion?

It is the minimum temperature required for a combustible substance to start burning.

What gases are commonly released from burning fossil fuels?

Carbon dioxide, carbon monoxide, sulfur dioxide, and nitrogen oxides.