Chapter 3: Combustion of Fuels - Fill in the Blanks

Fill-in-the-blank style flashcards covering CNG usage, matchstick chemistry, natural gas, properties of ideal fuels, pollution from combustion, energy conservation, non-conventional energy, and related health and environmental topics.

Compressed natural gas (CNG) is being used in vehicles like buses, cars, etc., to prevent air __.

pollution

The head of matchsticks are made of an oxidising agent such as __, mixed with sulfur, fillers and glass powder.

potassium chlorate

The side of the box contains red __, binder and powdered glass.

phosphorus

The heat generated by friction when the match is struck causes a minute amount of red phosphorus to be converted to __ phosphorus, which ignites spontaneously in air.

white

This sets off the decomposition of __ to give oxygen and potassium chloride.

potassium chlorate

In 1826, John __, a chemist in Stockton on Tees, discovered through lucky accident that a stick coated with chemicals burst into flame when scraped across his hearth at home.

Walker

Combustion of fuels causes __ and water vapour.

carbon dioxide

If sufficient supply of oxygen is not available, vapours of fuels do not undergo complete combustion and __ gas is formed.

carbon monoxide

Natural gas is a fossil fuel which is stored under high pressure as __.

compressed natural gas (CNG)

It consists mainly of methane (about __%) and occurs deep under the earth.

95

Natural gas advantages: (1) Natural gas has higher __ value than either petroleum (liquid) or coal (solid).

calorific

(2) It does not produce any __ gas or smoke on burning.

toxic

(3) It burns readily to produce __.

heat

(4) It is easy to transport. It can be supplied directly from the gas well to factories or homes through underground __.

pipelines

3.7 CHARACTERISTICS OF AN IDEAL FUEL The choice of an efficient fuel depends on the purpose… An ideal fuel must have high __ value.

calorific

An ideal fuel must: (2) have __ ignition temperature.

moderate

(3) not cause any pollution, i.e., it must neither produce harmful gases, nor leave any __.

residue

(4) be easily available and __.

economical

(5) be easy to transport and easy to __.

store

(6) burn at a __ rate.

moderate

(7) be easy to __.

handle

All fuels, including fossil fuels, produce __ and water vapour on combustion.

carbon dioxide

No fuel is 100% pure, so it produces other gases such as __ dioxide and nitrogen dioxide.

sulfur

This results in both soil and water __.

pollution

3.9 JUDICIOUS USE OF FOSSIL FUELS Fossil fuels, like coal, petroleum, and natural gas are __.

non-renewable

Preventing wastage of fuel in the kitchen by using a stove with higher __ of energy conversion.

efficiency

Soaking pulses in water for some time helps in reducing cooking __.

time

Cleaning of stoves, chulhas frequently to improve their __.

functioning

Use of __ transport instead of individual transport vehicles.

public

Switching off __, lights, etc., when not in use.

fans

Carbon monoxide poisoning can be __.

fatal

Soaking pulses in water for some time __ the functioning of a stove.

improves

The reason to use public transport instead of personal vehicles is to __.

reduce energy consumption and pollution

Name some non-conventional sources of energy: __.

solar energy, wind energy, tidal energy, ocean wave energy, and ocean thermal energy

Hydrogen has the highest calorific value but it is dangerous to handle as it burns with an __.

explosion

Hydrogen could very well turn out to be the fuel of the future due to the development of hydrogen __.

cells

Carbon monoxide combines with haemoglobin in our blood, stopping the supply of __.

oxygen

This gas released in atmosphere absorbs the sun's infrared radiation, which raises temperature on the earth. This causes global __.

warming

Various harmful gases released during burning of fuels combine with rain water and fall down as acid rain. The blank is: __ rain.

acid

Depletion of non-renewable sources has given rise to the __.

energy crisis